Creates a zero-length Buffer
.
Creates a new Buffer
with length
bytes. The contents are initialized to 0
.
The desired length of the new Buffer
.
Creates a new Buffer
copied from arrayLike
. TypedArray
will be treated as an Array
.
An array of bytes in the range 0
– 255
. Array entries outside that range will be truncated to fit into it.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf1 = Buffer.of(21, 31)
console.log(buf1.toString('hex')) // Prints: 151f
const buf2 = new Buffer(new Uint16Array([0x1234, 0x5678]))
console.log(buf2.toString('hex')) // Prints: 3478
const buf3 = Buffer.from('0102', 'hex')
const buf4 = new Buffer(buf3)
buf3[0] = 0x03
console.log(buf3.toString('hex')) // Prints: 0302
console.log(buf4.toString('hex')) // Prints: 0102
})()
Creates a view of the arrayBuffer
without copying the underlying memory. For example, when passed a reference to the .buffer
property of a TypedArray
instance, the newly created Buffer
will share the same allocated memory as the TypedArray
's underlying ArrayBuffer
.
An ArrayBuffer
or SharedArrayBuffer
, for example the .buffer
property of a TypedArray
.
Optional
byteOffset: numberIndex of first byte to expose. Default: 0
.
Optional
length: numberNumber of bytes to expose. Default: arrayBuffer.byteLength - byteOffset
.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const uint16 = new Uint16Array([5000, 4000])
const buf = Buffer.from(uint16.buffer) // Shares memory with `uint16`.
console.log(buf.toString('hex')) // Prints: 8813a00f
uint16[1] = 6000
console.log(buf.toString('hex')) // Prints: 88137017
})()
Static
ofThe static method creates a new Buffer
from a variable number of arguments.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf1 = Buffer.of(1)
console.log(buf1.toString('hex')) // Prints: 01
const buf2 = Buffer.of("1", "2", "3")
console.log(buf2.toString('hex')) // Prints: 010203
const buf3 = Buffer.of(undefined)
console.log(buf3.toString('hex')) // Prints: 00
})()
Static
allocAllocates a new Buffer
of size
bytes. If fill
is undefined
, the Buffer
will be zero-filled.
The desired length of the new Buffer
.
Optional
fill: number | Uint8Array<ArrayBufferLike> | BufferA value to pre-fill the new Buffer
with. Default: 0
.
Allocates a new Buffer
of size
bytes. If fill
is undefined
, the Buffer
will be zero-filled.
The desired length of the new Buffer
.
A value to pre-fill the new Buffer
with. Default: 0
.
Optional
encoding: The encoding of fill
. Default: 'utf8'
.
If fill
is specified, the allocated Buffer
will be initialized by calling buf.fill(fill)
.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf = Buffer.alloc(5, 'a')
console.log(buf.toString('hex')) // Prints: 6161616161
})()
If both fill
and encoding
are specified, the allocated Buffer
will be initialized by calling buf.fill(fill, encoding)
.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf = Buffer.alloc(11, 'aGVsbG8gd29ybGQ=', 'base64')
console.log(buf.toString('hex')) // Prints: 68656c6c6f20776f726c64
})()
Static
allocStatic
allocStatic
byteReturns .byteLength
if value
is a Buffer
/DataView
/TypedArray
/ArrayBuffer
/SharedArrayBuffer
.
A value to calculate the length of bytes.
The number of bytes contained within value
.
Returns the byte length of a string when encoded using encoding
. This is not the same as String.prototype.length
, which does not account for the encoding
that is used to convert the string into bytes.
For 'base64'
, 'base64url'
, and 'hex'
, this method assumes value
is valid. For strings that contain non-base64/hex-encoded data (e.g. whitespace), the return value might be greater than the length of a Buffer
created from the string.
A value to calculate the length of bytes.
Optional
encoding: The encoding of string
. Default: 'utf8'
.
The number of bytes contained within string
.
Static
compareCompares buf1
to buf2
, typically for the purpose of sorting arrays of Buffer
instances. This is equivalent to calling Buffer#compare.
Either -1
, 0
, or 1
, depending on the result of the comparison. See Buffer#compare for details.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf1 = Buffer.from('1234')
const buf2 = Buffer.from('0123')
console.log([buf1, buf2].sort(Buffer.compare).map(buf => buf.toString('hex')))
// Prints: ['30313233', '31323334']
// (This result is equal to: [buf2, buf1].)
console.log([buf2, buf1].sort(Buffer.compare).map(buf => buf.toString('hex')))
// Prints: ['30313233', '31323334']
})()
Static
concatReturns a new Buffer
which is the result of concatenating all the Buffer
instances in the list
together.
If the list
has no items, or if the totalLength
is 0, then a new zero-length Buffer
is returned.
If totalLength
is not provided, it is calculated from the Buffer
instances in list
by adding their lengths.
If totalLength
is provided, it is coerced to an unsigned integer. If the combined length of the Buffer
s in list
exceeds totalLength
, the result is truncated to totalLength
.
List of Buffer
or Uint8Array
instances to concatenate.
Optional
totalLength: numberTotal length of the Buffer
instances in list
when concatenated.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf1 = Buffer.alloc(4)
const buf2 = Buffer.alloc(5)
const buf3 = Buffer.alloc(6)
const totalLength = buf1.length + buf2.length + buf3.length
console.log(totalLength) // Prints: 15
const bufA = Buffer.concat([buf1, buf2, buf3], totalLength)
console.log(bufA.toString('hex'))
// Prints: 000000000000000000000000000000
console.log(bufA.length) // Prints: 15
})()
Static
copyCopies the underlying memory of view
into a new Buffer
.
The TypedArray
to copy.
The starting offset within view
. Default: 0
.
Optional
length: numberThe number of elements from view
to copy. Default: view.length - offset
.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const u16 = new Uint16Array([0, 0xffff])
const buf = Buffer.copyBytesFrom(u16, 1, 1)
u16[1] = 0
console.log(buf.length) // Prints: 2
console.log(buf.toString('hex')) // Prints: ffff
})()
Static
equalsture
if buf1
and buf2
have the same byte length and contents, or false
otherwise.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
console.log(Buffer.equals(Buffer.of(1, 2), Buffer.from('0102', 'hex'))) // true
console.log(Buffer.equals(Buffer.from(Uint8Array.of(1, 2)), Buffer.from('0102', 'hex'))) // true
console.log(Buffer.equals(Uint8Array.of(1, 2), Buffer.from('0102', 'hex'))) // false
console.log(Buffer.equals(1, Uint8Array.of(1, 2))) // false
console.log(Buffer.equals('', new Buffer(2))) // false
})()
Static
fromAllocates a new Buffer
using an array
of bytes in the range 0
– 255
. Array entries outside that range will be truncated to fit into it.
If array
is an Array
-like object (that is, one with a length
property of type number
), it is treated as if it is an array, unless it is a Buffer
or a Uint8Array
. This means all other TypedArray
variants get treated as an Array
. To create a Buffer
from the bytes backing a TypedArray
, use Buffer.copyBytesFrom.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf1 = Buffer.from([0x62, 0x75, 0x66, 0x66, 0x65, 0x72])
console.log(buf1.toString('hex')) // Prints: 627566666572
const u16 = new Uint16Array([0x0001, 0x0002])
const buf2 = Buffer.from(u16)
console.log(buf2.toString('hex')) // Prints: 0102
})()
This creates a view of the ArrayBuffer
without copying the underlying memory. For example, when passed a reference to the .buffer
property of a TypedArray
instance, the newly created Buffer
will share the same allocated memory as the TypedArray
's underlying ArrayBuffer
.
The optional byteOffset and length arguments specify a memory range within the arrayBuffer that will be shared by the Buffer.
It is important to remember that a backing ArrayBuffer
can cover a range of memory that extends beyond the bounds of a TypedArray
view. A new Buffer
created using the buffer
property of a TypedArray
may extend beyond the range of the TypedArray
:
An ArrayBuffer
, SharedArrayBuffer
, for example the .buffer
property of a TypedArray
.
Optional
byteOffset: numberIndex of first byte to expose. Default: 0
.
Optional
length: numberNumber of bytes to expose. Default: arrayBuffer.byteLength - byteOffset
.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const arr = new Uint16Array(2)
arr[0] = 5000
arr[1] = 4000
const buf = Buffer.from(arr.buffer) // Shares memory with `arr`
console.log(buf.toString('hex')) // Prints: 8813a00f
// Changing the original Uint16Array changes the Buffer also.
arr[1] = 6000
console.log(buf.toString('hex')) // Prints: 88137017
})()
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const ab = new ArrayBuffer(10)
const buf = Buffer.from(ab, 0, 2)
console.log(buf.length) // Prints: 2
})()
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const arrA = Uint8Array.from([0x63, 0x64, 0x65, 0x66]) // 4 elements
const arrB = new Uint8Array(arrA.buffer, 1, 2) // 2 elements
console.log(arrA.buffer === arrB.buffer) // true
const buf = Buffer.from(arrB.buffer)
console.log(buf.toString('hex')) // Prints: 63646566
})()
Copies the passed buffer
data onto a new Buffer
instance.
An existing Buffer
or Uint8Array
from which to copy data.
Restore a Buffer
in the format returned from Buffer#toJSON.
A JSON object returned from Buffer#toJSON.
Creates a new Buffer
containing string
. The encoding
parameter identifies the character encoding to be used when converting string
into bytes.
A string to encode.
Optional
encoding: The encoding of string. Default: 'utf8'
.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf1 = Buffer.from('this is a tést')
const buf2 = Buffer.from('7468697320697320612074c3a97374', 'hex')
console.log(buf1.toString()) // Prints: this is a tést
console.log(buf2.toString()) // Prints: this is a tést
console.log(buf1.toString('latin1')) // Prints: this is a tést
})()
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf = Buffer.from(new String('this is a test'))
console.log(buf.toString('hex')) // Prints: 7468697320697320612074657374
})()
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
class Foo {
[Symbol.toPrimitive]() {
return 'this is a test';
}
}
const buf = Buffer.from(new Foo(), 'utf8')
console.log(buf.toString('hex')) // Prints: 7468697320697320612074657374
})()
Static
fromCreates a new Buffer
that encoded from the provided base64
using Base64 encoding. When creating a Buffer
from a string, this encoding will also correctly accept "URL and Filename Safe Alphabet" as specified in RFC 4648, Section 5. Whitespace characters such as spaces, tabs, and new lines contained within the base64-encoded string are ignored.
A string to encode.
Static
fromCreates a new Buffer
that encoded from the provided base64
using base64url encoding. base64url encoding as specified in RFC 4648, Section 5. When creating a Buffer
from a string, this encoding will also correctly accept regular base64-encoded strings.
A string to encode.
Static
fromStatic
fromCreates a new Buffer
that encoded from the provided latin1
using Latin-1 encoding. Latin-1 stands for ISO-8859-1. This character encoding only supports the Unicode characters from U+0000 to U+00FF. Each character is encoded using a single byte. Characters that do not fit into that range are truncated and will be mapped to characters in that range.
A string to encode.
Static
fromCreates a new Buffer
that encoded from the provided string
. The encoding
parameter identifies the character encoding to be used when converting string
into bytes.
A string to encode.
The encoding of string
. Default: 'utf8'
.
Static
fromCreates a new Buffer
that encoded from the provided ucs2
using UCS-2 encoding. UCS-2 used to refer to a variant of UTF-16 that did not support characters that had code points larger than U+FFFF. In Node.js, these code points are always supported.
A string to encode.
Static
fromCreates a new Buffer
that encoded from the provided utf8
using UTF-8 encoding. Multi-byte encoded Unicode characters. Many web pages and other document formats use UTF-8. This is the default character encoding.
A string to encode.
This method based on the TextEncoder API.
Static
fromCreates a Buffer
from view
without copying the underlying memory.
The ArrayBufferView
to create a Buffer
from.
Optional
offset: numberThe starting offset within view
. Default: 0
.
Optional
length: numberThe number of elements from view
to copy. Default: view.length - offset
.
Static
istrue
if obj
is a Buffer
, false
otherwise.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
console.log(Buffer.isBuffer(Buffer.alloc(10))) // true
console.log(Buffer.isBuffer(Buffer.from('foo'))) // true
console.log(Buffer.isBuffer('a string')) // false
console.log(Buffer.isBuffer([])) // false
console.log(Buffer.isBuffer(new Uint8Array(1024))) // false
})()
Static
isA character encoding name to check.
true
if encoding
is the name of a supported character encoding, or false
otherwise.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
console.log(Buffer.isEncoding('utf8')) // true
console.log(Buffer.isEncoding('hex')) // true
console.log(Buffer.isEncoding('utf/8')) // false
console.log(Buffer.isEncoding('')) // false
})()
Static
iterIteratively unpack from the buf
according to the format string format
. This method returns an iterator which will read equally sized chunks from the buf
until remaining contents smaller then the size required by the format
, as reflected by Buffer.packCalcSize.
A Buffer
to unpack from.
A format string. Please refer to Buffer.packParseFormat for more information.
Static
packCreates a new Buffer
containing the vals
packed according to the format string format
. The arguments must match the vals
required by the format
exactly.
A format string. Please refer to Buffer.packParseFormat for more information.
Values to pack.
Unlike Python struct, this method does not support native size and alignment (that wouldn't make much sense in a javascript). Instead, specify byte order and emit pad bytes explicitly.
Please refer to Python struct — Interpret bytes as packed binary data for more information.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
console.log(Buffer.pack('>h', 1023).toString('hex')) // Prints: 03ff
console.log(Buffer.pack('<h', 1023).toString('hex')) // Prints: ff03
console.log(Buffer.pack('>bhl', 1, 2, 3).toString('hex')) // Prints: 01000200000003
})()
Pack vals
into buf
according to the format string format
. The arguments must match the vals
required by the format
exactly. The buf
’s size in bytes must larger then the size required by the format
, as reflected by Buffer.packCalcSize.
A Buffer
to pack into.
A format string. Please refer to Buffer.packParseFormat for more information.
Values to pack.
Unlike Python struct, this method does not support native size and alignment (that wouldn't make much sense in a javascript). Instead, specify byte order and emit pad bytes explicitly.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf1 = Buffer.alloc(3)
Buffer.pack(buf1, '>h', 0x0102)
console.log(buf1.toString('hex')) // Prints: 010200
const buf2 = Buffer.alloc(3)
Buffer.pack(buf2.subarray(1), '>h', 0x0102) // struct.pack_into
console.log(buf2.toString('hex')) // Prints: 000102
})()
Static
packReturn the required size corresponding to the format string formatOrItems
.
A format string or parsed items return by items of Buffer.packParseFormat.
Unlike Python struct, this method does not support native size and alignment (that wouldn't make much sense in a javascript). Instead, specify byte order and emit pad bytes explicitly.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
console.log(Buffer.packCalcSize('>bhl')) // Prints: 7
console.log(Buffer.packCalcSize('>ci')) // Prints: 5
console.log(Buffer.packCalcSize('>ic')) // Prints: 5
console.log(Buffer.packCalcSize('>lhl')) // Prints: 10
console.log(Buffer.packCalcSize('>llh')) // Prints: 10
console.log(Buffer.packCalcSize('>llh0l')) // Prints: 10
console.log(Buffer.packCalcSize('<qh6xq')) // Prints: 24
console.log(Buffer.packCalcSize('<qqh6x')) // Prints: 24
})()
Static
packParse a format string format
. This is a internal method used by Buffer.packCalcSize, Buffer.pack, Buffer.unpack and Buffer.iterUnpack.
A format string.
The first character of the format string can be used to indicate the byte order, size and alignment of the packed data, according to the following table:
Character | Byte order | Size | Alignment |
---|---|---|---|
@ |
native | standard | none |
= |
native | standard | none |
< |
little-endian | standard | none |
> |
big-endian | standard | none |
! |
big-endian | standard | none |
If the first character is not one of these, @
is assumed.
Format characters have the following meaning; the conversion between C and Python values should be obvious given their types. The ‘Size’ column refers to the size of the packed value in bytes.
Format | C Type | JavaScript Type | Size | Notes |
---|---|---|---|---|
x |
pad byte | no value | 1 | (1) |
c |
char |
Buffer of length 1 | 1 | |
b |
signed char |
number | 1 | |
B |
unsigned char |
number | 1 | |
? |
_Bool |
boolean | 1 | (2) |
h |
short |
number | 2 | |
H |
unsigned short |
number | 2 | |
i |
int |
number | 4 | |
I |
unsigned int |
number | 4 | |
l |
long |
number | 4 | |
L |
unsigned long |
number | 4 | |
q |
long long |
BigInt of 64 bits | 8 | |
Q |
unsigned long long |
BigInt of 64 bits | 8 | |
e |
(3) | number | 2 | (4) |
f |
float |
number | 4 | (4) |
d |
double |
number | 8 | (4) |
s |
char[] |
Buffer | (5) | |
p |
char[] |
Buffer | (6) |
Notes:
x
inserts one NUL byte (0x00
).?
conversion code corresponds to the _Bool type defined by C standards since C99. It is represented by one byte.6.1e-05
and 6.5e+04
at full precision. This type is not widely supported by C compilers: on a typical machine, an unsigned short can be used for storage, but not for math operations. See the Wikipedia page on the half-precision floating-point format for more information.f
, d
and e
conversion codes, the packed representation uses the IEEE 754 binary32, binary64 or binary16 format (for f
, d
or e
respectively), regardless of the floating-point format used by the platform.s
format character, the count is interpreted as the length of the bytes, not a repeat count like for the other format characters; for example, 10s
means a single 10-byte Buffer mapping to or from a single Buffer, while 10c
means 10 separate one byte character elements (e.g., cccccccccc
) mapping to or from ten different Buffer. (See Examples for a concrete demonstration of the difference.) If a count is not given, it defaults to 1
. For packing, the Buffer is truncated or padded with null bytes as appropriate to make it fit. For unpacking, the resulting Buffer always has exactly the specified number of bytes. As a special case, 0s
means a single, empty Buffer.p
format character encodes a "Pascal string", meaning a short variable-length string stored in a fixed number of bytes, given by the count. The first byte stored is the length of the string, or 255, whichever is smaller. The bytes of the string follow. If the string passed in to pack() is too long (longer than the count minus 1), only the leading count-1
bytes of the string are stored. If the string is shorter than count-1
, it is padded with null bytes so that exactly count bytes in all are used. Note that for unpack()
, the p
format character consumes count bytes, but that the string returned can never contain more than 255 bytes.A format character may be preceded by an integral repeat count. For example, the format string 4h
means exactly the same as hhhh
.
For the ?
format character, the return value is either true
or false
. When packing, the truth value of the argument object is used. Either 0
or 1
in the bool representation will be packed, and any non-zero value will be true
when unpacking.
Static
toStatic
toStatic
toStatic
toDecodes buf
to a string according to the Latin1 character encoding. When decoding a Buffer
into a string, using this encoding will additionally unset the highest bit of each byte before decoding as 'latin1'
. Generally, there should be no reason to use this encoding, as 'utf8' (or, if the data is known to always be ASCII-only, 'latin1'
) will be a better choice when encoding or decoding ASCII-only text. It is only provided for legacy compatibility.
The buffer to decode.
Static
toStatic
toDecodes buf
to a string according to the UTF-8 character encoding.
The buffer to decode.
This method based on the TextDecoder API.
Static
unpackUnpack from the buf
(presumably packed by pack(format, ...)
) according to the format string format
. The result is a tuple even if it contains exactly one item. The buf
’s size in bytes must larger then the size required by the format
, as reflected by Buffer.packCalcSize.
A Buffer
to unpack from.
A format string. Please refer to Buffer.packParseFormat for more information.
Implements the iterable protocol and allows Buffer
to be consumed by most syntaxes expecting iterables, such as the spread syntax and for...of loops. It returns an array iterator object that yields the value of each index in the Buffer
.
A new iterable iterator object that yields the value of each index in the Buffer
.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf1 = Buffer.of(10, 20, 30, 40, 50)
for (const n of buf1) console.log(n)
const values = buf1[Symbol.iterator]()
console.log(values.next().value) // Expected output: 10
console.log(values.next().value) // Expected output: 20
console.log(values.next().value) // Expected output: 30
console.log(values.next().value) // Expected output: 40
console.log(values.next().value) // Expected output: 50
})()
Takes an integer value and returns the item at that index, allowing for positive and negative integers. Negative integers count back from the last item in the Buffer
.
Zero-based index of the Buffer
element to be returned, converted to an integer. Negative index counts back from the end of the Buffer
— if index < 0
, index + array.length
is accessed.
The element in the Buffer
matching the given index. Always returns undefined
if index < -array.length
or index >= array.length
without attempting to access the corresponding property.
The method shallow copies part of this Buffer
to another location in the same Buffer
and returns this Buffer
without modifying its length.
Zero-based index at which to copy the sequence to. This corresponds to where the element at start will be copied to, and all elements between start and end are copied to succeeding indices.
Zero-based index at which to start copying elements from.
Optional
end: numberZero-based index at which to end copying elements from. This method copies up to but not including end.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf = new Buffer(8)
buf.set([1, 2, 3])
console.log(buf.toString('hex')) // Prints: 0102030000000000
buf.copyWithin(3, 0, 3)
console.log(buf.toString('hex')) // Prints: 0102030102030000
})()
Returns a new array iterator object that contains the key/value pairs for each index in the Buffer
.
A new iterable iterator object.
Tests whether all elements in the Buffer
pass the test implemented by the provided function.
A function to execute for each element in the Buffer
. It should return a truthy value to indicate the element passes the test, and a falsy value otherwise. The function is called with the following arguments:
value
: The current element being processed in the Buffer
.index
: The index of the current element being processed in the Buffer
.array
: The Buffer
every()
was called upon.Optional
thisArg: anyA value to use as this when executing callbackFn
.
true
unless callbackFn
returns a falsy value for a Buffer
element, in which case false
is immediately returned.
Creates a copy of a portion of a given Buffer
, filtered down to just the elements from the given Buffer
that pass the test implemented by the provided function.
A function to execute for each element in the Buffer
. It should return a truthy value to keep the element in the resulting Buffer
, and a falsy value otherwise. The function is called with the following arguments:
value
: The current element being processed in the Buffer
.index
: The index of the current element being processed in the Buffer
.array
: The Buffer
filter()
was called upon.Optional
thisArg: anyA value to use as this when executing callbackFn
.
A copy of the given Buffer
containing just the elements that pass the test. If no elements pass the test, an empty Buffer
is returned.
Returns the first element in the provided Buffer
that satisfies the provided testing function. If no values satisfy the testing function, undefined
is returned.
A function to execute for each element in the Buffer
. It should return a truthy value to indicate a matching element has been found, and a falsy value otherwise. The function is called with the following arguments:
value
: The current element being processed in the Buffer
.index
: The index of the current element being processed in the Buffer
.array
: The Buffer
find()
was called upon.Optional
thisArg: anyA value to use as this when executing callbackFn
.
The first element in the Buffer
that satisfies the provided testing function. Otherwise, undefined
is returned.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
function isPrime(element, index, array) {
let start = 2;
while (start <= Math.sqrt(element)) {
if (element % start++ < 1) {
return false;
}
}
return element > 1;
}
const buf = Buffer.of(4, 5, 8, 12)
console.log(buf.find(isPrime)) // Expected output: 5
})()
Returns the index of the first element in the Buffer
that satisfies the provided testing function. If no elements satisfy the testing function, -1
is returned.
A function to execute for each element in the Buffer
. It should return a truthy value to indicate a matching element has been found, and a falsy value otherwise. The function is called with the following arguments:
value
: The current element being processed in the Buffer
.index
: The index of the current element being processed in the Buffer
.array
: The Buffer
findIndex()
was called upon.Optional
thisArg: anyA value to use as this when executing callbackFn
.
The index of the first element in the Buffer
that passes the test. Otherwise, -1
.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
function isPrime(element, index, array) {
let start = 2;
while (start <= Math.sqrt(element)) {
if (element % start++ < 1) {
return false;
}
}
return element > 1;
}
console.log(Buffer.of(4, 6, 8, 12).findIndex(isPrime)) // Expected output: -1
console.log(Buffer.of(4, 6, 7, 12).findIndex(isPrime)) // Expected output: 2
})()
Iterates the Buffer
in reverse order and returns the value of the first element that satisfies the provided testing function. If no elements satisfy the testing function, undefined is returned.
A function to execute for each element in the Buffer
. It should return a truthy value to indicate a matching element has been found, and a falsy value otherwise. The function is called with the following arguments:
value
: The current element being processed in the Buffer
.index
: The index of the current element being processed in the Buffer
.array
: The Buffer
find()
was called upon.Optional
thisArg: anyA value to use as this when executing callbackFn
.
The last (highest-index) element in the Buffer
that satisfies the provided testing function; undefined
if no matching element is found.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
function isPrime(element, index, array) {
let start = 2;
while (start <= Math.sqrt(element)) {
if (element % start++ < 1) {
return false;
}
}
return element > 1;
}
const buf1 = Buffer.of(4, 6, 8, 12)
console.log(buf1.findLast(isPrime)) // Expected output: undefined
const buf2 = Buffer.of(4, 5, 7, 8, 9, 11, 12)
console.log(buf2.findLast(isPrime)) // Expected output: 11
})()
Iterates the Buffer
in reverse order and returns the index of the first element that satisfies the provided testing function. If no elements satisfy the testing function, -1
is returned.
A function to execute for each element in the Buffer
. It should return a truthy value to indicate a matching element has been found, and a falsy value otherwise. The function is called with the following arguments:
value
: The current element being processed in the Buffer
.index
: The index of the current element being processed in the Buffer
.array
: The Buffer
findIndex()
was called upon.Optional
thisArg: anyA value to use as this when executing callbackFn
.
The index of the last (highest-index) element in the Buffer
that passes the test. Otherwise -1
if no matching element is found.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
function isPrime(element, index, array) {
let start = 2;
while (start <= Math.sqrt(element)) {
if (element % start++ < 1) {
return false;
}
}
return element > 1;
}
console.log(Buffer.of(4, 6, 8, 12).findLastIndex(isPrime)) // Expected output: -1
console.log(Buffer.of(4, 5, 7, 8, 9, 11, 12).findLastIndex(isPrime)) // Expected output: 5
})()
Executes a provided function once for each Buffer
element.
A function to execute for each element in the Buffer
. Its return value is discarded. The function is called with the following arguments:
value
: The current element being processed in the Buffer
.index
: The index of the current element being processed in the Buffer
.array
: The Buffer
forEach()
was called upon.Optional
thisArg: anyA value to use as this
when executing callbackfn
.
Creates and returns a new string by concatenating all of the elements in this Buffer
, separated by commas or a specified separator string. If the Buffer
has only one item, then that item will be returned without using the separator.
Optional
separator: stringA string to separate each pair of adjacent elements of the Buffer
. If omitted, the Buffer
elements are separated with a comma ","
.
A string with all Buffer
elements joined. If buf.length
is 0, the empty string is returned.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf = Buffer.of(1, 2, 3)
console.log(buf.join()) // Expected output: "1,2,3"
console.log(buf.join(" / ")) // Expected output: "1 / 2 / 3"
console.log(buf.join('')) // Expected output: "123"
})()
Returns a new array iterator object that contains the keys for each index in the Buffer
.
A new iterable iterator object.
Creates a new Buffer
populated with the results of calling a provided function on every element in the calling Buffer
.
A function to execute for each element in the Buffer
. Its return value is added as a single element in the new Buffer
. The function is called with the following arguments:
value
: The current element being processed in the Buffer
.index
: The index of the current element being processed in the Buffer
.array
: The Buffer
map()
was called upon.Optional
thisArg: anyA value to use as this
when executing callbackfn
.
A new Buffer
with each element being the result of the callback function.
Calls the specified callback function for all the elements in an array. The return value of the callback function is the accumulated result, and is provided as an argument in the next call to the callback function.
A function that accepts up to four arguments. The reduce method calls the callbackfn
function one time for each element in the array.
Optional
initialValue: TIf initialValue
is specified, it is used as the initial value to start the accumulation. The first call to the callbackfn
function provides this value as an argument instead of an array value.
Calls the specified callback function for all the elements in an array, in descending order. The return value of the callback function is the accumulated result, and is provided as an argument in the next call to the callback function.
A function that accepts up to four arguments. The reduceRight method calls
the callbackfn
function one time for each element in the array.
Optional
initialValue: TIf initialValue
is specified, it is used as the initial value to start
the accumulation. The first call to the callbackfn
function provides this value as an argument
instead of an array value.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf = Buffer.of(10, 20, 30)
const result = buf.reduceRight((accumulator, currentValue) => `${accumulator}, ${currentValue}`)
console.log(result) // Expected output: "30, 20, 10"
})()
The method reverses a Buffer
in place and returns the reference to the same Buffer
, the first element now becoming the last, and the last element becoming the first. In other words, elements order in the Buffer
will be turned towards the direction opposite to that previously stated.
Stores multiple values in the Buffer
, reading input values from a specified array
.
The array from which to copy values. All values from the source array
are copied into the Buffer
, unless the length of the source array
plus the target offset exceeds the length of the Buffer
, in which case an exception is thrown. If the source array
is a Buffer
, the two arrays may share the same underlying ArrayBuffer; the JavaScript engine will intelligently copy the source range of the buffer to the destination range.
Optional
offset: numberThe offset into the Buffer
at which to begin writing values from the source array
. If this value is omitted, 0 is assumed (that is, the source array
will overwrite values in the Buffer
starting at index 0).
Returns a copy of a portion of a Buffer
into a new Buffer
object selected from start
to end
(end
not included) where start
and end
represent the index of items in that buf
. The original Buffer
will not be modified.
Optional
start: numberWhere the new Buffer
will start. Default: 0
.
Optional
end: numberWhere the new Buffer
will end (not inclusive). Default: buf.length
.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf1 = Buffer.from('1020304050', 'hex')
const buf2 = buf1.slice(1, 3)
buf1[1] = 0x60
console.log(buf1.toString('hex')) // Prints: 1060304050
console.log(buf2.toString('hex')) // Prints: 2030
})()
Tests whether at least one element in the Buffer
passes the test implemented by the provided function. It returns true if, in the Buffer
, it finds an element for which the provided function returns true; otherwise it returns false. It doesn't modify the Buffer
.
A function to execute for each element in the Buffer
. It should return a truthy value to indicate the element passes the test, and a falsy value otherwise. The function is called with the following arguments:
value
: The current element being processed in the Buffer
.index
: The index of the current element being processed in the Buffer
.array
: The Buffer
some()
was called upon.Optional
thisArg: anyA value to use as this
when executing callbackFn
.
false
unless callbackFn returns a truthy value for a Buffer
element, in which case true
is immediately returned.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const isBiggerThan10 = (value, index, array) => value > 10
console.log(Buffer.of(2, 5, 8, 1, 4).some(isBiggerThan10)) // Expected output: false
console.log(Buffer.of(12, 5, 8, 1, 4).some(isBiggerThan10)) // Expected output: true
})()
The method sorts the elements of a Buffer
in place and returns the reference to the same Buffer
, now sorted.
Optional
compareFn: (a: number, b: number) => anyA function that determines the order of the elements. The function is called with the following arguments:
a
: The first element for comparison.b
: The second element for comparison.
It should return a number where:a
should come before b
.a
should come after b
.NaN
indicates that a
and b
are considered equal.
To memorize this, remember that (a, b) => a - b
sorts numbers in ascending order. If omitted, the elements are sorted according to numeric value.The reference to the original Buffer
, now sorted. Note that the Buffer
is sorted in place, and no copy is made.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf1 = Buffer.from('03010204', 'hex')
buf1.sort()
console.log(buf1.toString('hex')) // Prints: 01020304
buf1.sort((a, b) => b - a)
console.log(buf1.toString('hex')) // Prints: 04030201
})()
Returns a new Buffer
that references the same memory as the original, but offset and cropped by the start
and end
indexes.
Specifying end
greater than buf.length
will return the same result as that of end
equal to buf.length
.
Modifying the new Buffer
slice will modify the memory in the original Buffer
because the allocated memory of the two objects overlap.
Specifying negative indexes causes the slice to be generated relative to the end of buf
rather than the beginning.
Optional
start: numberWhere the new Buffer
will start. Default: 0
.
Optional
end: numberWhere the new Buffer
will end (not inclusive). Default: buf.length
.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf1 = Buffer.allocUnsafe(26)
for (let i = 0; i < 26; i++) buf1[i] = i + 97
const buf2 = buf1.subarray(0, 3)
console.log(buf2.toString('ascii', 0, buf2.length)) // Prints: abc
buf1[0] = 33
console.log(buf2.toString('ascii', 0, buf2.length)) // Prints: !bc
})()
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf1 = Buffer.allocUnsafe(26)
for (let i = 0; i < 26; i++) buf1[i] = i + 97
const buf2 = buf1.subarray(0, 3)
console.log(buf2.toString('ascii', 0, buf2.length)) // Prints: abc
buf1[0] = 33
console.log(buf2.toString('ascii', 0, buf2.length)) // Prints: !bc
})()
Returns a string representing the elements of the Buffer
. The elements are converted to strings using their toLocaleString methods and these strings are separated by a locale-specific string (such as a comma ",").
Optional
locales: string | string[]A string with a BCP 47 language tag, or an array of such strings. For the general form and interpretation of the locales argument, see the parameter description on the Intl main page.
Optional
options: NumberFormatOptionsAn object with configuration properties. See Number.prototype.toLocaleString().
A string representing the elements of the Buffer
.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf = Buffer.of(200, 50, 81, 12, 42)
console.log(buf.toLocaleString()) // Expected output: "200,50,81,12,42"
console.log(buf.toLocaleString('en-US')) // Expected output: "200,50,81,12,42"
console.log(buf.toLocaleString('ja-JP', { style: 'currency', currency: 'JPY' })) // Expected output: "¥200,¥50,¥81,¥12,¥42"
})()
Returns a new array iterator object that iterates the value of each item in the Buffer
.
A new iterable iterator object.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf1 = Buffer.of(10, 20, 30, 40, 50)
for (const n of buf1.values()) console.log(n)
const values = buf1.values()
console.log(values.next().value) // Expected output: 10
console.log(values.next().value) // Expected output: 20
console.log(values.next().value) // Expected output: 30
console.log(values.next().value) // Expected output: 40
console.log(values.next().value) // Expected output: 50
})()
Calculates the Bitwise AND of all bytes in this
. If this
is empty, returns 0xFF
. You can use Buffer#subarray to calculate the Bitwise AND of a subset of this
.
The Bitwise AND of all bytes in buf
.
The method Bitwise AND every bytes with other
in place and returns this
. If length of other
is shorter than this
, the remaining bytes in this
will not be changed. If length of other
is longer than this
, the remaining bytes in other
will be ignored.
A Buffer
to Bitwise AND with.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf1 = Buffer.from('010203', 'hex')
const buf2 = Buffer.from('102030', 'hex')
console.log(buf1.and(buf2).toString('hex')) // Prints: 000000
console.log(buf1.toString('hex')) // Prints: 000000
})()
Compares buf
with target
and returns a number indicating whether buf
comes before, after, or is the same as target
in sort order. Comparison is based on the actual sequence of bytes in each Buffer
.
The optional targetStart
, targetEnd
, sourceStart
, and sourceEnd
arguments can be used to limit the comparison to specific ranges within target
and buf
respectively.
A Buffer
or Uint8Array
with which to compare buf
.
The offset within target
at which to begin comparison. Default: 0
.
The offset within target
at which to end comparison (not inclusive). Default: target.length
.
The offset within buf
at which to begin comparison. Default: 0
.
The offset within buf at which to end comparison (not inclusive). Default: this.length
.
0
is returned if target
is the same as buf
1
is returned if target
should come before buf
when sorted.-1
is returned if target
should come after buf
when sorted.;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf1 = Buffer.from('ABC')
const buf2 = Buffer.from('BCD')
const buf3 = Buffer.from('ABCD')
console.log(buf1.compare(buf1)) // Prints: 0
console.log(buf1.compare(buf2)) // Prints: -1
console.log(buf1.compare(buf3)) // Prints: -1
console.log(buf2.compare(buf1)) // Prints: 1
console.log(buf2.compare(buf3)) // Prints: 1
console.log([buf1, buf2, buf3].sort(Buffer.compare).map(buf => buf.toString()))
// Prints: ['ABC', 'ABCD', 'BCD']
})()
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf1 = Buffer.from([1, 2, 3, 4, 5, 6, 7, 8, 9])
const buf2 = Buffer.from([5, 6, 7, 8, 9, 1, 2, 3, 4])
console.log(buf1.compare(buf2, 5, 9, 0, 4)) // Prints: 0
console.log(buf1.compare(buf2, 0, 6, 4)) // Prints: -1
console.log(buf1.compare(buf2, 5, 6, 5)) // Prints: 1
})()
Copies data from a region of buf
to a region in target
, even if the target
memory region overlaps with buf
.
TypedArray.prototype.set()
performs the same operation, and is available for all TypedArrays, including Node.js Buffer
s, although it takes different function arguments.
A Buffer
or Uint8Array
to copy into.
The offset within target
at which to begin writing. Default: 0
.
The offset within buf
from which to begin copying. Default: 0
.
The offset within buf
at which to stop copying (not inclusive). Default: this.length
.
The number of bytes copied.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf1 = Buffer.allocUnsafe(26)
const buf2 = Buffer.allocUnsafe(26).fill('!')
// 97 is the decimal ASCII value for 'a'.
for (let i = 0; i < 26; i++) buf1[i] = i + 97
// Copy `buf1` bytes 16 through 19 into `buf2` starting at byte 8 of `buf2`.
buf1.copy(buf2, 8, 16, 20)
// This is equivalent to:
// buf2.set(buf1.subarray(16, 20), 8)
console.log(buf2.toString('ascii', 0, 25))
// Prints: !!!!!!!!qrst!!!!!!!!!!!!!
})()
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
// Create a `Buffer` and copy data from one region to an overlapping region within the same `Buffer`.
const buf = Buffer.allocUnsafe(26)
// 97 is the decimal ASCII value for 'a'.
for (let i = 0; i < 26; i++) buf[i] = i + 97
buf.copy(buf, 0, 4, 10)
console.log(buf.toString())
// Prints: efghijghijklmnopqrstuvwxyz
})()
A Buffer or Uint8Array with which to compare buf.
true
if both buf
and otherBuffer
have exactly the same bytes, false
otherwise. Equivalent to buf.compare(otherBuffer) === 0
.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf1 = Buffer.from('ABC')
const buf2 = Buffer.from('414243', 'hex')
const buf3 = Buffer.from('ABCD')
console.log(buf1.equals(buf2)) // Prints: true
console.log(buf1.equals(buf3)) // Prints: false
})()
Fill the entire buf
with the specified value
.
The value with which to fill buf. Empty string is coerced to 0
.
Optional
encoding: The encoding for value
. Default: 'utf8'
.
Fill the buf
with the specified value
start from offset
.
The value with which to fill buf. Empty string is coerced to 0
.
Number of bytes to skip before starting to fill buf
. Default: 0
.
Optional
encoding: The encoding for value
. Default: 'utf8'
.
Fill the buf
with the specified value
start from offset
and stop before end
.
The value with which to fill buf. Empty string is coerced to 0
.
Number of bytes to skip before starting to fill buf
. Default: 0
.
Where to stop filling buf
(not inclusive). Default: buf.length
.
Optional
encoding: The encoding for value
. Default: 'utf8'
.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
// Fill a `Buffer` with the ASCII character 'h'.
const b = Buffer.allocUnsafe(10).fill('h')
console.log(b.toString()) // Prints: hhhhhhhhhh
// Fill a buffer with empty string
const c = Buffer.allocUnsafe(5).fill('')
console.log(c.toString('hex')) // Prints: 0000000000
})()
If the final write of a fill()
operation falls on a multi-byte character, then only the bytes of that character that fit into buf
are written:
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
// Fill a `Buffer` with character that takes up two bytes in UTF-8.
const b = Buffer.allocUnsafe(5).fill('\u0222')
console.log(b.toString('hex')) // Prints: c8a2c8a2c8
})()
If value
contains invalid characters, it is truncated; if no valid fill data remains, an exception is thrown:
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf = Buffer.allocUnsafe(5)
console.log(buf.fill('a').toString('hex')) // Prints: 6161616161
console.log(buf.fill('aazz', 'hex').toString('hex')) // Prints: aaaaaaaaaa
console.log(buf.fill('zz', 'hex').toString('hex')) // Throws an exception.
})()
Fill buf
with the specified value
. If the offset
and end
are not given, the entire buf
will be filled.
The value with which to fill buf
. Empty value (Uint8Array, Buffer) is coerced to 0
. value
is coerced to a uint32
value if it is not a string, Buffer
, or integer. If the resulting integer is greater than 255
(decimal), buf
will be filled with value & 255
.
Optional
offset: numberNumber of bytes to skip before starting to fill buf
. Default: 0
.
Optional
end: numberWhere to stop filling buf
(not inclusive). Default: buf.length
.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
// Fill a `Buffer` with a Buffer
const buf1 = Buffer.allocUnsafe(10).fill(Buffer.of(65))
console.log(buf1.toString()) // Prints: AAAAAAAAAA
// Fill a `Buffer` with an Uint8Array
const buf2 = Buffer.allocUnsafe(10).fill(Uint8Array.of(65))
console.log(buf2.toString()) // Prints: AAAAAAAAAA
// Fill a `Buffer` with number
const buf3 = Buffer.allocUnsafe(10).fill(65)
console.log(buf3.toString()) // Prints: AAAAAAAAAA
})()
Alias of DataView.getBigInt64.
Optional
littleEndian: booleanAlias of DataView.getBigUint64.
Optional
littleEndian: booleanPolyfill of DataView.getFloat16.
Alias of DataView.getFloat32.
Optional
littleEndian: booleanAlias of DataView.getFloat64.
Optional
littleEndian: booleanAlias of DataView.getInt16.
Optional
littleEndian: booleanAlias of DataView.getInt32.
Optional
littleEndian: booleanAlias of DataView.getInt8.
Alias of DataView.getUint16.
Optional
littleEndian: booleanAlias of DataView.getUint32.
Optional
littleEndian: booleanAlias of DataView.getUint8.
Equivalent to buf.indexOf() !== -1
.
What to search for.
Optional
encoding: The encoding of value
. Default: 'utf8'
.
true
if value
was found in buf
, false
otherwise.
Equivalent to buf.indexOf() !== -1
.
What to search for.
Where to begin searching in buf
. If negative, then offset is calculated from the end of buf
. Default: 0
.
Optional
encoding: The encoding of value
. Default: 'utf8'
.
true
if value
was found in buf
, false
otherwise.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf = Buffer.from('this is a buffer')
console.log(buf.includes('this')) // Prints: true
console.log(buf.includes('is')) // Prints: true
console.log(buf.includes('this', 4)) // Prints: false
})()
Equivalent to buf.indexOf() !== -1
.
What to search for.
Optional
byteOffset: numberWhere to begin searching in buf
. If negative, then offset is calculated from the end of buf
. Default: 0
.
true
if value
was found in buf
, false
otherwise.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf = Buffer.from('this is a buffer')
console.log(buf.includes(Buffer.from('a buffer'))) // Prints: true
console.log(buf.includes(97)) // Prints: true (97 is the decimal ASCII value for 'a')
console.log(buf.includes(Uint8Array.of(97))) // Prints: true (97 is the decimal ASCII value for 'a')
console.log(buf.includes(Buffer.from('a buffer example'))) // Prints: false
console.log(buf.includes(Buffer.from('a buffer example').slice(0, 8))) // Prints: true
})()
What to search for.
value
is a string, value
is interpreted according to the character encoding in encoding
.value
is a Buffer
or Uint8Array
, value
will be used in its entirety. To compare a partial Buffer, use Buffer#subarray.value
is a number, it will be coerced to a valid byte value, an integer between 0
and 255
.value
is an empty string or empty Buffer and byteOffset
is less than buf.length
, byteOffset
will be returned.value
is empty and byteOffset
is at least buf.length
, buf.length
will be returned.Optional
encoding: The encoding of value
. Default: 'utf8'
.
value
in buf
-1
if buf
does not contain value.What to search for.
value
is a string, value
is interpreted according to the character encoding in encoding
.value
is a Buffer
or Uint8Array
, value
will be used in its entirety. To compare a partial Buffer, use Buffer#subarray.value
is a number, it will be coerced to a valid byte value, an integer between 0
and 255
.value
is an empty string or empty Buffer and byteOffset
is less than buf.length
, byteOffset
will be returned.value
is empty and byteOffset
is at least buf.length
, buf.length
will be returned.Where to begin searching in buf
. Default: 0
.
buf
._.toSafeInteger
.Optional
encoding: The encoding of value
. Default: 'utf8'
.
value
in buf
-1
if buf
does not contain value.;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf = Buffer.from('this is a buffer')
console.log(buf.indexOf('this')) // Prints: 0
console.log(buf.indexOf('is')) // Prints: 2
const utf16Buffer = Buffer.from('\u039a\u0391\u03a3\u03a3\u0395', 'utf16le')
console.log(utf16Buffer.indexOf('\u03a3', 0, 'utf16le')) // Prints: 4
console.log(utf16Buffer.indexOf('\u03a3', -4, 'utf16le')) // Prints: 6
})()
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const b = Buffer.from('abcdef')
// Passing a byteOffset that coerces to 0.
// Prints: 1, searching the whole buffer.
console.log(b.indexOf('b', undefined))
console.log(b.indexOf('b', {}))
console.log(b.indexOf('b', null))
console.log(b.indexOf('b', []))
})()
What to search for.
value
is a string, value
is interpreted according to the character encoding in encoding
.value
is a Buffer
or Uint8Array
, value
will be used in its entirety. To compare a partial Buffer, use Buffer#subarray.value
is a number, it will be coerced to a valid byte value, an integer between 0
and 255
.value
is an empty string or empty Buffer and byteOffset
is less than buf.length
, byteOffset
will be returned.value
is empty and byteOffset
is at least buf.length
, buf.length
will be returned.Optional
byteOffset: numberWhere to begin searching in buf
. Default: 0
.
buf
._.toSafeInteger
.value
in buf
-1
if buf
does not contain value.;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf = Buffer.from('this is a buffer')
console.log(buf.indexOf(Buffer.from('a buffer'))) // Prints: 8
console.log(buf.indexOf(97)) // Prints: 8 (97 is the decimal ASCII value for 'a')
console.log(buf.indexOf(Buffer.from('a buffer example'))) // Prints: -1
console.log(buf.indexOf(Buffer.from('a buffer example').slice(0, 8))) // Prints: 8
})()
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const b = Buffer.from('abcdef')
// Passing a value that's a number, but not a valid byte.
// Prints: 2, equivalent to searching for 99 or 'c'.
console.log(b.indexOf(99.9))
console.log(b.indexOf(256 + 99))
})()
Iteratively unpack from the buf
according to the format string format
. This method returns an iterator which will read equally sized chunks from the buf
until remaining contents smaller then the size required by the format
, as reflected by Buffer.packCalcSize.
A format string. Please refer to Buffer.packParseFormat for more information.
Identical to Buffer#indexOf, except the last occurrence of value
is found rather than the first occurrence.
What to search for.
value
is a string, value
is interpreted according to the character encoding in encoding
.value
is a Buffer
or Uint8Array
, value
will be used in its entirety. To compare a partial Buffer, use Buffer#subarray.value
is a number, it will be coerced to a valid byte value, an integer between 0
and 255
.value
is an empty string or empty Buffer
, byteOffset
will be returned.Optional
encoding: The encoding of value
. Default: 'utf8'
.
value
in buf
-1
if buf
does not contain value
.Identical to Buffer#indexOf, except the last occurrence of value
is found rather than the first occurrence.
What to search for.
value
is a string, value
is interpreted according to the character encoding in encoding
.value
is a Buffer
or Uint8Array
, value
will be used in its entirety. To compare a partial Buffer, use Buffer#subarray.value
is a number, it will be coerced to a valid byte value, an integer between 0
and 255
.value
is an empty string or empty Buffer
, byteOffset
will be returned.Where to begin searching in buf
. Default: buf.length - 1
.
buf
._.toSafeInteger
.Optional
encoding: The encoding of value
. Default: 'utf8'
.
value
in buf
-1
if buf
does not contain value
.;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf = Buffer.from('this buffer is a buffer')
console.log(buf.lastIndexOf('this')) // Prints: 0
console.log(buf.lastIndexOf('buffer')) // Prints: 17
console.log(buf.lastIndexOf('buffer', 5)) // Prints: 5
console.log(buf.lastIndexOf('buffer', 4)) // Prints: -1
const utf16Buffer = Buffer.from('\u039a\u0391\u03a3\u03a3\u0395', 'utf16le')
console.log(utf16Buffer.lastIndexOf('\u03a3', undefined, 'utf16le')) // Prints: 6
console.log(utf16Buffer.lastIndexOf('\u03a3', -5, 'utf16le')) // Prints: 4
})()
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const b = Buffer.from('abcdef')
// Passing a byteOffset that coerces to NaN.
// Prints: 1, searching the whole buffer.
console.log(b.lastIndexOf('b', undefined))
console.log(b.lastIndexOf('b', {}))
// Passing a byteOffset that coerces to 0.
// Prints: -1, equivalent to passing 0.
console.log(b.lastIndexOf('b', null))
console.log(b.lastIndexOf('b', []))
})()
Identical to Buffer#indexOf, except the last occurrence of value
is found rather than the first occurrence.
What to search for.
value
is a number, it will be coerced to a valid byte value, an integer between 0
and 255
.value
is an empty string or empty Buffer
, byteOffset
will be returned.Optional
byteOffset: numberWhere to begin searching in buf
. Default: buf.length - 1
.
buf
._.toSafeInteger
.value
in buf
-1
if buf
does not contain value
.;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf = Buffer.from('this buffer is a buffer')
console.log(buf.lastIndexOf(Buffer.from('buffer'))) // Prints: 17
console.log(buf.lastIndexOf(97)) // Prints: 15 (97 is the decimal ASCII value for 'a')
console.log(buf.lastIndexOf(Buffer.from('yolo'))) // Prints: -1
})()
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const b = Buffer.from('abcdef')
// Passing a value that's a number, but not a valid byte.
// Prints: 2, equivalent to searching for 99 or 'c'.
console.log(b.lastIndexOf(99.9))
console.log(b.lastIndexOf(256 + 99))
})()
Calculates the Bitwise OR of all bytes in buf
. If buf
is empty, returns 0
. You can use Buffer#subarray to calculate the Bitwise OR of a subset of buf
.
The Bitwise OR of all bytes in buf
.
The method Bitwise OR every bytes with other
in place and returns this
. If length of other
is shorter than this
, the remaining bytes in this
will not be changed. If length of other
is longer than this
, the remaining bytes in other
will be ignored.
A Buffer
to Bitwise OR with.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf1 = Buffer.from('010203', 'hex')
const buf2 = Buffer.from('102030', 'hex')
console.log(buf1.or(buf2).toString('hex')) // Prints: 112233
console.log(buf1.toString('hex')) // Prints: 112233
})()
Pack vals
into buf
according to the format string format
. The arguments must match the vals
required by the format
exactly. The buf
’s size in bytes must larger then the size required by the format
, as reflected by Buffer.packCalcSize.
A format string. Please refer to Buffer.packParseFormat for more information.
Values to pack.
Unlike Python struct, this method does not support native size and alignment (that wouldn't make much sense in a javascript). Instead, specify byte order and emit pad bytes explicitly.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf1 = Buffer.alloc(3)
buf1.pack('>h', 0x0102)
console.log(buf1.toString('hex')) // Prints: 010200
const buf2 = Buffer.alloc(3)
buf2.subarray(1).pack('>h', 0x0102) // struct.pack_into
console.log(buf2.toString('hex')) // Prints: 000102
})()
Reads a signed, big-endian 64-bit integer from buf
at the specified offset
. Integers read from a Buffer
are interpreted as two's complement signed values.
Number of bytes to skip before starting to read. Must satisfy: 0 <= offset <= buf.length - 8
. Default: 0
.
Reads a signed, little-endian 64-bit integer from buf
at the specified offset
. Integers read from a Buffer
are interpreted as two's complement signed values.
Number of bytes to skip before starting to read. Must satisfy: 0 <= offset <= buf.length - 8
. Default: 0
.
Treat the buffer as a least significant bit array and read a bit at the specified bit offset.
bit offset to read from.
Treat buf
as a most-significant bit array and read a bit at the specified bit offset.
bit offset to read from.
Reads a 16-bit, big-endian float from buf
at the specified offset
.
Number of bytes to skip before starting to read. Must satisfy 0 <= offset <= buf.length - 2
. Default: 0
.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
console.log(Buffer.from('0000', 'hex').readFloat16BE(0)) // Prints: 0
console.log(Buffer.from('8000', 'hex').readFloat16BE(0)) // Prints: -0
console.log(Buffer.from('3c00', 'hex').readFloat16BE(0)) // Prints: 1
console.log(Buffer.from('bc00', 'hex').readFloat16BE(0)) // Prints: -1
console.log(Buffer.from('7c00', 'hex').readFloat16BE(0)) // Prints: Infinity
console.log(Buffer.from('fc00', 'hex').readFloat16BE(0)) // Prints: -Infinity
console.log(Buffer.from('7e00', 'hex').readFloat16BE(0)) // Prints: NaN
console.log(Buffer.from('fe00', 'hex').readFloat16BE(0)) // Prints: NaN
})()
Reads a 16-bit, little-endian float from buf
at the specified offset
.
Number of bytes to skip before starting to read. Must satisfy 0 <= offset <= buf.length - 2
. Default: 0
.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
console.log(Buffer.from('0000', 'hex').readFloat16LE(0)) // Prints: 0
console.log(Buffer.from('0080', 'hex').readFloat16LE(0)) // Prints: -0
console.log(Buffer.from('003c', 'hex').readFloat16LE(0)) // Prints: 1
console.log(Buffer.from('00bc', 'hex').readFloat16LE(0)) // Prints: -1
console.log(Buffer.from('007c', 'hex').readFloat16LE(0)) // Prints: Infinity
console.log(Buffer.from('00fc', 'hex').readFloat16LE(0)) // Prints: -Infinity
console.log(Buffer.from('007e', 'hex').readFloat16LE(0)) // Prints: NaN
console.log(Buffer.from('00fe', 'hex').readFloat16LE(0)) // Prints: NaN
})()
Reads a signed, big-endian 16-bit integer from buf
at the specified offset
. Integers read from a Buffer
are interpreted as two's complement signed values.
Number of bytes to skip before starting to read. Must satisfy 0 <= offset <= buf.length - 2
. Default: 0
.
Reads a signed, little-endian 16-bit integer from buf
at the specified offset
. Integers read from a Buffer
are interpreted as two's complement signed values.
Number of bytes to skip before starting to read. Must satisfy 0 <= offset <= buf.length - 2
. Default: 0
.
Reads a signed, big-endian 32-bit integer from buf
at the specified offset
. Integers read from a Buffer
are interpreted as two's complement signed values.
Number of bytes to skip before starting to read. Must satisfy 0 <= offset <= buf.length - 4
. Default: 0
.
Reads a signed, little-endian 32-bit integer from buf
at the specified offset
. Integers read from a Buffer
are interpreted as two's complement signed values.
Number of bytes to skip before starting to read. Must satisfy 0 <= offset <= buf.length - 4
. Default: 0
.
Reads a signed 8-bit integer from buf
at the specified offset
. Integers read from a Buffer
are interpreted as two's complement signed values.
Number of bytes to skip before starting to read. Must satisfy 0 <= offset <= buf.length - 1
. Default: 0
.
Reads byteLength
number of bytes from buf
at the specified offset
and interprets the result as a big-endian, two's complement signed value supporting up to 48 bits of accuracy.
Number of bytes to skip before starting to read. Must satisfy 0 <= offset <= buf.length - byteLength
.
Number of bytes to read. Must satisfy 1 <= byteLength <= 6
.
Reads byteLength
number of bytes from buf
at the specified offset
and interprets the result as a little-endian, two's complement signed value supporting up to 48 bits of accuracy.
Number of bytes to skip before starting to read. Must satisfy 0 <= offset <= buf.length - byteLength
.
Number of bytes to read. Must satisfy 1 <= byteLength <= 6
.
Reads byteLength
number of bytes from buf
at the specified offset
and interprets the result as an unsigned big-endian integer supporting up to 48 bits of accuracy.
Number of bytes to skip before starting to read. Must satisfy 0 <= offset <= buf.length - byteLength
.
Number of bytes to read. Must satisfy 0 < byteLength <= 6
.
Reads byteLength
number of bytes from buf
at the specified offset
and interprets the result as an unsigned big-endian integer supporting up to 48 bits of accuracy.
Number of bytes to skip before starting to read. Must satisfy 0 <= offset <= buf.length - byteLength
.
Number of bytes to read. Must satisfy 0 < byteLength <= 6
.
Alias of DataView.setBigInt64.
Optional
littleEndian: booleanAlias of DataView.setBigUint64.
Optional
littleEndian: booleanPolyfill of DataView.setFloat16.
Alias of DataView.setFloat32.
Optional
littleEndian: booleanAlias of DataView.setFloat64.
Optional
littleEndian: booleanAlias of DataView.setInt16.
Optional
littleEndian: booleanAlias of DataView.setInt32.
Optional
littleEndian: booleanAlias of DataView.setInt8.
Alias of DataView.setUint16.
Optional
littleEndian: booleanAlias of DataView.setUint32.
Optional
littleEndian: booleanAlias of DataView.setUint8.
Interprets buf
as an array of unsigned 16-bit integers and swaps the byte order in-place.
A reference to buf
.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf1 = Buffer.from('0102030405060708', 'hex')
console.log(buf1.toString('hex')) // Prints: 0102030405060708
buf1.swap16()
console.log(buf1.toString('hex')) // Prints: 0201040306050807
const utf16 = Buffer.from('This is little-endian UTF-16', 'utf16le')
utf16.swap16() // Convert to big-endian UTF-16 text.
})()
Interprets buf
as an array of unsigned 32-bit integers and swaps the byte order in-place.
A reference to buf
.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf1 = Buffer.from('0102030405060708', 'hex')
console.log(buf1.toString('hex')) // Prints: 0102030405060708
buf1.swap32()
console.log(buf1.toString('hex')) // Prints: 0403020108070605
})()
Interprets buf
as an array of unsigned 64-bit integers and swaps the byte order in-place.
A reference to buf
.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf1 = Buffer.from('0102030405060708', 'hex')
console.log(buf1.toString('hex')) // Prints: 0102030405060708
buf1.swap64()
console.log(buf1.toString('hex')) // Prints: 0807060504030201
})()
The method returns a new Buffer
which is the Bitwise AND of this
and other
. If length of other
is shorter than this
, the remaining bytes in this
will be copied to the new Buffer
. If length of other
is longer than this
, the remaining bytes in other
will be ignored.
A Buffer
to Bitwise AND with.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf1 = Buffer.from('010203', 'hex')
const buf2 = Buffer.from('102030', 'hex')
console.log(buf1.toAnded(buf2).toString('hex')) // Prints: 000000
console.log(buf1.toString('hex')) // Prints: 010203
})()
JSON.stringify()
implicitly calls this method when stringifying a Buffer
instance. Buffer.from accepts objects in the format returned from this method. In particular, Buffer.from(buf.toJSON())
works like Buffer.from(buf)
.
a JSON representation of buf
.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf = Buffer.from('0102030405', 'hex')
const json = JSON.stringify(buf)
console.log(json) // Prints: {"type":"Buffer","data":[1,2,3,4,5]}
const restored = JSON.parse(json, (key, value) => {
return value && value.type === 'Buffer' ? Buffer.from(value) : value
})
console.log(restored.toString('hex')) // Prints: 0102030405
})()
The method returns a new Buffer
which is the Bitwise OR of this
and other
. If length of other
is shorter than this
, the remaining bytes in this
will be copied to the new Buffer
. If length of other
is longer than this
, the remaining bytes in other
will be ignored.
A Buffer
to Bitwise OR with.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf1 = Buffer.from('010203', 'hex')
const buf2 = Buffer.from('102030', 'hex')
console.log(buf1.toOred(buf2).toString('hex')) // Prints: 112233
console.log(buf1.toString('hex')) // Prints: 010203
})()
The method is the copying counterpart of the reverse()
method. It returns a new Buffer
with the elements in reversed order.
A new Buffer
containing the elements in reversed order.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf1 = Buffer.from('01020304', 'hex')
const buf2 = buf1.reverse()
console.log(buf1.toString('hex')) // Prints: 01020304
console.log(buf2.toString('hex')) // Prints: 04030201
})()
The method is the copying version of the sort()
method. It returns a new Buffer
with the elements sorted in ascending order.
Optional
compareFn: (a: number, b: number) => anyA function that determines the order of the elements. The function is called with the following arguments:
a
: The first element for comparison.b
: The second element for comparison.
It should return a number where:a
should come before b
.a
should come after b
.NaN
indicates that a
and b
are considered equal.
To memorize this, remember that (a, b) => a - b
sorts numbers in ascending order. If omitted, the elements are sorted according to numeric value.A new Buffer
with the elements sorted in ascending order.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf1 = Buffer.from('03010204', 'hex')
const buf2 = buf1.toSorted()
console.log(buf1.toString('hex')) // Prints: 03010204
console.log(buf2.toString('hex')) // Prints: 01020304
})()
Decodes buf
to a string according to the specified character encoding in encoding
. start
and end
may be passed to decode only a subset of buf
.
The character encoding to use. Default: 'utf8'
.
The byte offset to start decoding at. Default: 0
.
The byte offset to stop decoding at (not inclusive). Default: buf.length
.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf1 = Buffer.allocUnsafe(26)
for (let i = 0; i < 26; i++) buf1[i] = i + 97 // 97 is the decimal ASCII value for 'a'.
console.log(buf1.toString('utf8')) // Prints: abcdefghijklmnopqrstuvwxyz
console.log(buf1.toString('utf8', 0, 5)) // Prints: abcde
const buf2 = Buffer.from('tést')
console.log(buf2.toString('hex')) // Prints: 74c3a97374
console.log(buf2.toString('utf8', 0, 3)) // Prints: té
console.log(buf2.toString(undefined, 0, 3)) // Prints: té
})()
The method returns a new Buffer
which is the Bitwise XOR of this
and other
. If length of other
is shorter than this
, the remaining bytes in this
will be copied to the new Buffer
. If length of other
is longer than this
, the remaining bytes in other
will be ignored.
A Buffer
to Bitwise XOR with.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf1 = Buffer.from('010203', 'hex')
const buf2 = Buffer.from('102030', 'hex')
console.log(buf1.toXored(buf2).toString('hex')) // Prints: 112233
console.log(buf1.toString('hex')) // Prints: 010203
})()
Unpack from the buf
(presumably packed by pack(format, ...))
according to the format string format
. The result is a tuple even if it contains exactly one item. The buf
’s size in bytes must larger then the size required by the format
, as reflected by Buffer.packCalcSize.
A format string. Please refer to Buffer.packParseFormat for more information.
The method is the copying version of using the bracket notation to change the value of a given index. It returns a new Buffer
with the element at the given index replaced with the given value.
Zero-based index at which to change the Buffer
, converted to an integer.
Any value to be assigned to the given index.
A new Buffer
with the element at index replaced with value.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf1 = Buffer.from('0102030405', 'hex')
const buf2 = buf1.with(2, 6)
console.log(buf1.toString('hex')) // Prints: 0102030405
console.log(buf2.toString('hex')) // Prints: 0102060405
})()
Writes string
to buf
at offset
according to the character encoding inencoding
. The length
parameter is the number of bytes to write. If buf
did
not contain enough space to fit the entire string, only part of string
will be
written. However, partially encoded characters will not be written.
import { Buffer } from 'node:buffer';
const buf = Buffer.alloc(256);
const len = buf.write('\u00bd + \u00bc = \u00be', 0);
console.log(`${len} bytes: ${buf.toString('utf8', 0, len)}`);
// Prints: 12 bytes: ½ + ¼ = ¾
const buffer = Buffer.alloc(10);
const length = buffer.write('abcd', 8);
console.log(`${length} bytes: ${buffer.toString('utf8', 8, 10)}`);
// Prints: 2 bytes : ab
String to write to buf
.
Optional
encoding: The character encoding of string
.
Number of bytes written.
Optional
encoding: Writes string
to buf
at offset
according to the character encoding in encoding
. The length
parameter is the number of bytes to write. If buf
did not contain enough space to fit the entire string, only part of string
will be written. However, partially encoded characters will not be written.
String to write to buf
.
Number of bytes to skip before starting to write string
. Default: 0
.
Maximum number of bytes to write (written bytes will not exceed buf.length - offset
). Default: buf.length - offset
.
Optional
encoding: The character encoding of string
. Default: 'utf8'
.
Number of bytes written.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf1 = Buffer.alloc(256)
const len1 = buf1.write('\u00bd + \u00bc = \u00be', 0)
console.log(`${len1} bytes: ${buf1.toString('utf8', 0, len1)}`)
// Prints: 12 bytes: ½ + ¼ = ¾
const buf2 = Buffer.alloc(10)
const len2 = buf2.write('abcd', 8)
console.log(`${len2} bytes: ${buf2.toString('utf8', 8, 10)}`)
// Prints: 2 bytes : ab
})()
Writes value
to buf
at the specified offset
as big-endian. value
is interpreted and written as a two's complement signed integer.
Number to be written to buf
.
Number of bytes to skip before starting to write. Must satisfy: 0 <= offset <= buf.length - 8
. Default: 0
.
Writes value
to buf
at the specified offset
as little-endian. value
is interpreted and written as a two's complement signed integer.
Number to be written to buf
.
Number of bytes to skip before starting to write. Must satisfy: 0 <= offset <= buf.length - 8
. Default: 0
.
Writes value
to buf
at the specified offset
as little-endian.
Number to be written to buf
.
Number of bytes to skip before starting to write. Must satisfy: 0 <= offset <= buf.length - 8
. Default: 0
.
Treats buf
as a least significant bit array and write a bit at the specified bit offset.
Bit value to write.
bit offset to read from.
Treats buf
as a most-significant bit array and write a bit at the specified bit offset.
Bit value to write.
bit offset to read from.
Writes value
to buf
at the specified offset
as big-endian. The value
must be a JavaScript number. Behavior is undefined when value
is anything other than a JavaScript number.
Number to be written to buf
.
Number of bytes to skip before starting to write. Must satisfy: 0 <= offset <= buf.length - 8
. Default: 0
.
Writes value
to buf
at the specified offset
as little-endian. The value
must be a JavaScript number. Behavior is undefined when value
is anything other than a JavaScript number.
Number to be written to buf
.
Number of bytes to skip before starting to write. Must satisfy: 0 <= offset <= buf.length - 8
. Default: 0
.
Writes a 16-bit float value
to buf
at the specified offset
as big-endian. The value
must be a JavaScript number. Behavior is undefined when value
is anything other than a JavaScript number.
Number to be written to buf
.
Number of bytes to skip before starting to write. Must satisfy: 0 <= offset <= buf.length - 2
. Default: 0
.
Writes a 16-bit float value
to buf
at the specified offset
as little-endian. The value
must be a JavaScript number. Behavior is undefined when value
is anything other than a JavaScript number.
Number to be written to buf
.
Number of bytes to skip before starting to write. Must satisfy: 0 <= offset <= buf.length - 2
. Default: 0
.
Writes value
to buf
at the specified offset
as big-endian. The value
must be a JavaScript number. Behavior is undefined when value
is anything other than a JavaScript number.
Number to be written to buf
.
Number of bytes to skip before starting to write. Must satisfy: 0 <= offset <= buf.length - 4
. Default: 0
.
Writes value
to buf
at the specified offset
as little-endian. The value
must be a JavaScript number. Behavior is undefined when value
is anything other than a JavaScript number.
Number to be written to buf
.
Number of bytes to skip before starting to write. Must satisfy: 0 <= offset <= buf.length - 4
. Default: 0
.
Writes value
to buf
at the specified offset
as big-endian. The value must be a valid signed 16-bit integer. Behavior is undefined when value
is anything other than a signed 16-bit integer. The value
is interpreted and written as a two's complement signed integer.
Number to be written to buf
.
Number of bytes to skip before starting to write. Must satisfy: 0 <= offset <= buf.length - 2
. Default: 0
.
Writes value
to buf
at the specified offset
as little-endian. The value must be a valid signed 16-bit integer. Behavior is undefined when value
is anything other than a signed 16-bit integer. The value
is interpreted and written as a two's complement signed integer.
Number to be written to buf
.
Number of bytes to skip before starting to write. Must satisfy: 0 <= offset <= buf.length - 2
. Default: 0
.
Writes value
to buf
at the specified offset
as big-endian. The value must be a valid signed 32-bit integer. Behavior is undefined when value
is anything other than a signed 32-bit integer. The value
is interpreted and written as a two's complement signed integer.
Number to be written to buf
.
Number of bytes to skip before starting to write. Must satisfy: 0 <= offset <= buf.length - 4
. Default: 0
.
Writes value
to buf
at the specified offset
as little-endian. The value must be a valid signed 32-bit integer. Behavior is undefined when value
is anything other than a signed 32-bit integer. The value
is interpreted and written as a two's complement signed integer.
Number to be written to buf
.
Number of bytes to skip before starting to write. Must satisfy: 0 <= offset <= buf.length - 4
. Default: 0
.
Writes value
to buf
at the specified offset
. value
must be a valid signed 8-bit integer. Behavior is undefined when value
is anything other than a signed 8-bit integer. value
is interpreted and written as a two's complement signed integer.
Number to be written to buf
.
Number of bytes to skip before starting to write. Must satisfy: 0 <= offset <= buf.length - 1
. Default: 0
.
Writes byteLength
bytes of value
to buf
at the specified offset
as big-endian. Supports up to 48 bits of accuracy. Behavior is undefined when value
is anything other than a signed integer.
Number to be written to buf
.
Number of bytes to skip before starting to write. Must satisfy 0 <= offset <= buf.length - byteLength
.
Number of bytes to write. Must satisfy 1 <= byteLength <= 6
.
Writes byteLength
bytes of value
to buf
at the specified offset
as little-endian. Supports up to 48 bits of accuracy. Behavior is undefined when value
is anything other than a signed integer.
Number to be written to buf
.
Number of bytes to skip before starting to write. Must satisfy 0 <= offset <= buf.length - byteLength
.
Number of bytes to write. Must satisfy 1 <= byteLength <= 6
.
Writes value
to buf
at the specified offset
as big-endian. The value
must be a valid unsigned 16-bit integer. Behavior is undefined when value
is anything other than an unsigned 16-bit integer.
Number to be written to buf
.
Number of bytes to skip before starting to write. Must satisfy 0 <= offset <= buf.length - 2
. Default: 0
.
Writes value
to buf
at the specified offset
as little-endian. The value
must be a valid unsigned 16-bit integer. Behavior is undefined when value
is anything other than an unsigned 16-bit integer.
Number to be written to buf
.
Number of bytes to skip before starting to write. Must satisfy 0 <= offset <= buf.length - 2
. Default: 0
.
Writes value
to buf
at the specified offset
as big-endian. The value
must be a valid unsigned 32-bit integer. Behavior is undefined when value
is anything other than an unsigned 32-bit integer.
Number to be written to buf
.
Number of bytes to skip before starting to write. Must satisfy 0 <= offset <= buf.length - 4
. Default: 0
.
Writes value
to buf
at the specified offset
as little-endian. The value
must be a valid unsigned 32-bit integer. Behavior is undefined when value
is anything other than an unsigned 32-bit integer.
Number to be written to buf
.
Number of bytes to skip before starting to write. Must satisfy 0 <= offset <= buf.length - 4
. Default: 0
.
Writes value
to buf
at the specified offset
. value
must be a valid unsigned 8-bit integer. Behavior is undefined when value
is anything other than an unsigned 8-bit integer.
Number to be written to buf
.
Number of bytes to skip before starting to write. Must satisfy 0 <= offset <= buf.length - 1
. Default: 0
.
Writes byteLength
bytes of value
to buf
at the specified offset
as big-endian. Supports up to 48 bits of accuracy. Behavior is undefined when value
is anything other than an unsigned integer.
Number to be written to buf
.
Number of bytes to skip before starting to write. Must satisfy 0 <= offset <= buf.length - byteLength
.
Number of bytes to write. Must satisfy 1 <= byteLength <= 6
.
Writes byteLength
bytes of value
to buf
at the specified offset
as little-endian. Supports up to 48 bits of accuracy. Behavior is undefined when value
is anything other than an unsigned integer.
Number to be written to buf
.
Number of bytes to skip before starting to write. Must satisfy 0 <= offset <= buf.length - byteLength
.
Number of bytes to write. Must satisfy 1 <= byteLength <= 6
.
Calculates the Bitwise XOR of all bytes in buf
. If buf
is empty, returns 0
. You can use Buffer#subarray to calculate the Bitwise XOR of a subset of buf
. Xor is usually used to calculate checksums in serial communication.
The Bitwise XOR of all bytes in buf
.
The method Bitwise XOR every bytes with other
in place and returns this
. If length of other
is shorter than this
, the remaining bytes in this
will not be changed. If length of other
is longer than this
, the remaining bytes in other
will be ignored.
A Buffer
to Bitwise XOR with.
;(async function () {
const { Buffer } = await import('https://cdn.jsdelivr.net/npm/@taichunmin/buffer@0/+esm')
const buf1 = Buffer.from('010203', 'hex')
const buf2 = Buffer.from('102030', 'hex')
console.log(buf1.xor(buf2).toString('hex')) // Prints: 112233
console.log(buf1.toString('hex')) // Prints: 112233
})()
Alias of Buffer.readBigUInt64BE.
Alias of Buffer.readBigUInt64LE.
Alias of Buffer.readUInt16BE.
Alias of Buffer.readUInt16LE.
Alias of Buffer.readUInt32BE.
Alias of Buffer.readUInt32LE.
Alias of Buffer.readUInt8.
Alias of Buffer.readUIntBE.
Alias of Buffer.readUIntLE.
Alias of Buffer.writeBigUInt64BE.
Alias of Buffer.writeBigUInt64LE.
Alias of Buffer.writeUInt16BE.
Alias of Buffer.writeUInt16LE.
Alias of Buffer.writeUInt32BE.
Alias of Buffer.writeUInt32LE.
Alias of Buffer.writeUInt8.
Alias of Buffer.writeUIntBE.
Alias of Buffer.writeUIntLE.
Readonly
bufferThe underlying ArrayBuffer
object based on which this Buffer
object is created.
Readonly
byteThe length in bytes of the array.
Readonly
byteThe offset in bytes of the array.
Readonly
BYTES_The size in bytes of each element in the array.
Readonly
lengthThe length of the array.
Static
Readonly
BYTES_The size in bytes of each element in the array.
The
Buffer
class is a cross platform alternative of Node buffer base onUInt8Array
.See
See the Buffer | Node.js Documentation for more information.