Options
All
  • Public
  • Public/Protected
  • All
Menu

Hierarchy

  • Uint8Array
    • Buffer

Index

Properties

BYTES_PER_ELEMENT: number

The size in bytes of each element in the array.

[toStringTag]: "Uint8Array"

The ArrayBuffer instance referenced by the array.

byteLength: number

The length in bytes of the array.

byteOffset: number

The offset in bytes of the array.

length: number

The length of the array.

Methods

  • Returns IterableIterator<number>

  • at(index: number): number
  • 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 array.

    Parameters

    • index: number

    Returns number

  • compare(target: Uint8Array, targetStart?: number, targetEnd?: number, sourceStart?: number, sourceEnd?: number): 0 | 1 | -1
  • Compares buf with target and returns a number indicating whether bufcomes before, after, or is the same as target in sort order. Comparison is based on the actual sequence of bytes in each Buffer.

    • 0 is returned if target is the same as buf
    • 1 is returned if target should come beforebuf when sorted.
    • -1 is returned if target should come afterbuf when sorted.
    import { Buffer } from 'buffer';

    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));
    // Prints: [ <Buffer 41 42 43>, <Buffer 41 42 43 44>, <Buffer 42 43 44> ]
    // (This result is equal to: [buf1, buf3, buf2].)

    The optional targetStart, targetEnd, sourceStart, and sourceEndarguments can be used to limit the comparison to specific ranges within targetand buf respectively.

    import { Buffer } from 'buffer';

    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

    ERR_OUT_OF_RANGE is thrown if targetStart < 0, sourceStart < 0,targetEnd > target.byteLength, or sourceEnd > source.byteLength.

    since

    v0.11.13

    Parameters

    • target: Uint8Array

      A Buffer or {@link Uint8Array} with which to compare buf.

    • Optional targetStart: number
    • Optional targetEnd: number
    • Optional sourceStart: number
    • Optional sourceEnd: number

    Returns 0 | 1 | -1

  • copy(target: Uint8Array, targetStart?: number, sourceStart?: number, sourceEnd?: number): number
  • Copies data from a region of buf to a region in target, even if the targetmemory region overlaps with buf.

    TypedArray.prototype.set() performs the same operation, and is available for all TypedArrays, including Node.js Buffers, although it takes different function arguments.

    import { Buffer } from 'buffer';

    // Create two `Buffer` instances.
    const buf1 = Buffer.allocUnsafe(26);
    const buf2 = Buffer.allocUnsafe(26).fill('!');

    for (let i = 0; i < 26; i++) {
    // 97 is the decimal ASCII value for 'a'.
    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!!!!!!!!!!!!!
    import { Buffer } from 'buffer';

    // Create a `Buffer` and copy data from one region to an overlapping region
    // within the same `Buffer`.

    const buf = Buffer.allocUnsafe(26);

    for (let i = 0; i < 26; i++) {
    // 97 is the decimal ASCII value for 'a'.
    buf[i] = i + 97;
    }

    buf.copy(buf, 0, 4, 10);

    console.log(buf.toString());
    // Prints: efghijghijklmnopqrstuvwxyz
    since

    v0.1.90

    Parameters

    • target: Uint8Array

      A Buffer or {@link Uint8Array} to copy into.

    • Optional targetStart: number
    • Optional sourceStart: number
    • Optional sourceEnd: number

    Returns number

    The number of bytes copied.

  • Returns the this object after copying a section of the array identified by start and end to the same array starting at position target

    Parameters

    • target: number

      If target is negative, it is treated as length+target where length is the length of the array.

    • start: number

      If start is negative, it is treated as length+start. If end is negative, it is treated as length+end.

    • Optional end: number

      If not specified, length of the this object is used as its default value.

    Returns <internal>.Buffer

  • Creates and returns an iterator of [index, byte] pairs from the contents of buf.

    import { Buffer } from 'buffer';

    // Log the entire contents of a `Buffer`.

    const buf = Buffer.from('buffer');

    for (const pair of buf.entries()) {
    console.log(pair);
    }
    // Prints:
    // [0, 98]
    // [1, 117]
    // [2, 102]
    // [3, 102]
    // [4, 101]
    // [5, 114]
    since

    v1.1.0

    Returns IterableIterator<[number, number]>

  • equals(otherBuffer: Uint8Array): boolean
  • Returns true if both buf and otherBuffer have exactly the same bytes,false otherwise. Equivalent to buf.compare(otherBuffer) === 0.

    import { Buffer } from 'buffer';

    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
    since

    v0.11.13

    Parameters

    • otherBuffer: Uint8Array

      A Buffer or {@link Uint8Array} with which to compare buf.

    Returns boolean

  • every(predicate: ((value: number, index: number, array: Uint8Array) => unknown), thisArg?: any): boolean
  • Determines whether all the members of an array satisfy the specified test.

    Parameters

    • predicate: ((value: number, index: number, array: Uint8Array) => unknown)

      A function that accepts up to three arguments. The every method calls the predicate function for each element in the array until the predicate returns a value which is coercible to the Boolean value false, or until the end of the array.

        • (value: number, index: number, array: Uint8Array): unknown
        • Parameters

          • value: number
          • index: number
          • array: Uint8Array

          Returns unknown

    • Optional thisArg: any

      An object to which the this keyword can refer in the predicate function. If thisArg is omitted, undefined is used as the this value.

    Returns boolean

  • Fills buf with the specified value. If the offset and end are not given, the entire buf will be filled:

    import { Buffer } from 'buffer';

    // Fill a `Buffer` with the ASCII character 'h'.

    const b = Buffer.allocUnsafe(50).fill('h');

    console.log(b.toString());
    // Prints: hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh

    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 &#x26; 255.

    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:

    import { Buffer } from 'buffer';

    // Fill a `Buffer` with character that takes up two bytes in UTF-8.

    console.log(Buffer.allocUnsafe(5).fill('\u0222'));
    // Prints: <Buffer c8 a2 c8 a2 c8>

    If value contains invalid characters, it is truncated; if no valid fill data remains, an exception is thrown:

    import { Buffer } from 'buffer';

    const buf = Buffer.allocUnsafe(5);

    console.log(buf.fill('a'));
    // Prints: <Buffer 61 61 61 61 61>
    console.log(buf.fill('aazz', 'hex'));
    // Prints: <Buffer aa aa aa aa aa>
    console.log(buf.fill('zz', 'hex'));
    // Throws an exception.
    since

    v0.5.0

    Parameters

    • value: string | number | Uint8Array

      The value with which to fill buf.

    • Optional offset: number
    • Optional end: number
    • Optional encoding: BufferEncoding

    Returns <internal>.Buffer

    A reference to buf.

  • filter(predicate: ((value: number, index: number, array: Uint8Array) => any), thisArg?: any): Uint8Array
  • Returns the elements of an array that meet the condition specified in a callback function.

    Parameters

    • predicate: ((value: number, index: number, array: Uint8Array) => any)

      A function that accepts up to three arguments. The filter method calls the predicate function one time for each element in the array.

        • (value: number, index: number, array: Uint8Array): any
        • Parameters

          • value: number
          • index: number
          • array: Uint8Array

          Returns any

    • Optional thisArg: any

      An object to which the this keyword can refer in the predicate function. If thisArg is omitted, undefined is used as the this value.

    Returns Uint8Array

  • find(predicate: ((value: number, index: number, obj: Uint8Array) => boolean), thisArg?: any): number
  • Returns the value of the first element in the array where predicate is true, and undefined otherwise.

    Parameters

    • predicate: ((value: number, index: number, obj: Uint8Array) => boolean)

      find calls predicate once for each element of the array, in ascending order, until it finds one where predicate returns true. If such an element is found, find immediately returns that element value. Otherwise, find returns undefined.

        • (value: number, index: number, obj: Uint8Array): boolean
        • Parameters

          • value: number
          • index: number
          • obj: Uint8Array

          Returns boolean

    • Optional thisArg: any

      If provided, it will be used as the this value for each invocation of predicate. If it is not provided, undefined is used instead.

    Returns number

  • findIndex(predicate: ((value: number, index: number, obj: Uint8Array) => boolean), thisArg?: any): number
  • Returns the index of the first element in the array where predicate is true, and -1 otherwise.

    Parameters

    • predicate: ((value: number, index: number, obj: Uint8Array) => boolean)

      find calls predicate once for each element of the array, in ascending order, until it finds one where predicate returns true. If such an element is found, findIndex immediately returns that element index. Otherwise, findIndex returns -1.

        • (value: number, index: number, obj: Uint8Array): boolean
        • Parameters

          • value: number
          • index: number
          • obj: Uint8Array

          Returns boolean

    • Optional thisArg: any

      If provided, it will be used as the this value for each invocation of predicate. If it is not provided, undefined is used instead.

    Returns number

  • forEach(callbackfn: ((value: number, index: number, array: Uint8Array) => void), thisArg?: any): void
  • Performs the specified action for each element in an array.

    Parameters

    • callbackfn: ((value: number, index: number, array: Uint8Array) => void)

      A function that accepts up to three arguments. forEach calls the callbackfn function one time for each element in the array.

        • (value: number, index: number, array: Uint8Array): void
        • Parameters

          • value: number
          • index: number
          • array: Uint8Array

          Returns void

    • Optional thisArg: any

      An object to which the this keyword can refer in the callbackfn function. If thisArg is omitted, undefined is used as the this value.

    Returns void

  • Equivalent to buf.indexOf() !== -1.

    import { Buffer } from 'buffer';

    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(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(Buffer.from('a buffer example')));
    // Prints: false
    console.log(buf.includes(Buffer.from('a buffer example').slice(0, 8)));
    // Prints: true
    console.log(buf.includes('this', 4));
    // Prints: false
    since

    v5.3.0

    Parameters

    Returns boolean

    true if value was found in buf, false otherwise.

  • indexOf(value: string | number | Uint8Array, byteOffset?: number, encoding?: BufferEncoding): number
  • If value is:

    • a string, value is interpreted according to the character encoding inencoding.
    • a Buffer or Uint8Array, value will be used in its entirety. To compare a partial Buffer, use buf.slice().
    • a number, value will be interpreted as an unsigned 8-bit integer value between 0 and 255.
    import { Buffer } from 'buffer';

    const buf = Buffer.from('this is a buffer');

    console.log(buf.indexOf('this'));
    // Prints: 0
    console.log(buf.indexOf('is'));
    // Prints: 2
    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

    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

    If value is not a string, number, or Buffer, this method will throw aTypeError. If value is a number, it will be coerced to a valid byte value, an integer between 0 and 255.

    If byteOffset is not a number, it will be coerced to a number. If the result of coercion is NaN or 0, then the entire buffer will be searched. This behavior matches String.prototype.indexOf().

    import { Buffer } from 'buffer';

    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));

    // Passing a byteOffset that coerces to NaN or 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', []));

    If value is an empty string or empty Buffer and byteOffset is less than buf.length, byteOffset will be returned. If value is empty andbyteOffset is at least buf.length, buf.length will be returned.

    since

    v1.5.0

    Parameters

    • value: string | number | Uint8Array

      What to search for.

    • Optional byteOffset: number
    • Optional encoding: BufferEncoding

    Returns number

    The index of the first occurrence of value in buf, or -1 if buf does not contain value.

  • join(separator?: string): string
  • Adds all the elements of an array separated by the specified separator string.

    Parameters

    • Optional separator: string

      A string used to separate one element of an array from the next in the resulting String. If omitted, the array elements are separated with a comma.

    Returns string

  • Creates and returns an iterator of buf keys (indices).

    import { Buffer } from 'buffer';

    const buf = Buffer.from('buffer');

    for (const key of buf.keys()) {
    console.log(key);
    }
    // Prints:
    // 0
    // 1
    // 2
    // 3
    // 4
    // 5
    since

    v1.1.0

    Returns IterableIterator<number>

  • lastIndexOf(value: string | number | Uint8Array, byteOffset?: number, encoding?: BufferEncoding): number
  • Identical to buf.indexOf(), except the last occurrence of value is found rather than the first occurrence.

    import { Buffer } from 'buffer';

    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.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
    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

    If value is not a string, number, or Buffer, this method will throw aTypeError. If value is a number, it will be coerced to a valid byte value, an integer between 0 and 255.

    If byteOffset is not a number, it will be coerced to a number. Any arguments that coerce to NaN, like {} or undefined, will search the whole buffer. This behavior matches String.prototype.lastIndexOf().

    import { Buffer } from 'buffer';

    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));

    // 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', []));

    If value is an empty string or empty Buffer, byteOffset will be returned.

    since

    v6.0.0

    Parameters

    • value: string | number | Uint8Array

      What to search for.

    • Optional byteOffset: number
    • Optional encoding: BufferEncoding

    Returns number

    The index of the last occurrence of value in buf, or -1 if buf does not contain value.

  • map(callbackfn: ((value: number, index: number, array: Uint8Array) => number), thisArg?: any): Uint8Array
  • Calls a defined callback function on each element of an array, and returns an array that contains the results.

    Parameters

    • callbackfn: ((value: number, index: number, array: Uint8Array) => number)

      A function that accepts up to three arguments. The map method calls the callbackfn function one time for each element in the array.

        • (value: number, index: number, array: Uint8Array): number
        • Parameters

          • value: number
          • index: number
          • array: Uint8Array

          Returns number

    • Optional thisArg: any

      An object to which the this keyword can refer in the callbackfn function. If thisArg is omitted, undefined is used as the this value.

    Returns Uint8Array

  • readBigInt64BE(offset?: number): bigint
  • 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.

    since

    v12.0.0, v10.20.0

    Parameters

    • Optional offset: number

    Returns bigint

  • readBigInt64LE(offset?: number): bigint
  • Reads a signed, little-endian 64-bit integer from buf at the specifiedoffset.

    Integers read from a Buffer are interpreted as two's complement signed values.

    since

    v12.0.0, v10.20.0

    Parameters

    • Optional offset: number

    Returns bigint

  • readBigUInt64BE(offset?: number): bigint
  • Reads an unsigned, big-endian 64-bit integer from buf at the specifiedoffset.

    This function is also available under the readBigUint64BE alias.

    import { Buffer } from 'buffer';

    const buf = Buffer.from([0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff]);

    console.log(buf.readBigUInt64BE(0));
    // Prints: 4294967295n
    since

    v12.0.0, v10.20.0

    Parameters

    • Optional offset: number

    Returns bigint

  • readBigUInt64LE(offset?: number): bigint
  • Reads an unsigned, little-endian 64-bit integer from buf at the specifiedoffset.

    This function is also available under the readBigUint64LE alias.

    import { Buffer } from 'buffer';

    const buf = Buffer.from([0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff]);

    console.log(buf.readBigUInt64LE(0));
    // Prints: 18446744069414584320n
    since

    v12.0.0, v10.20.0

    Parameters

    • Optional offset: number

    Returns bigint

  • readBigUint64BE(offset?: number): bigint
  • alias

    Buffer.readBigUInt64BE

    since

    v14.10.0, v12.19.0

    Parameters

    • Optional offset: number

    Returns bigint

  • readBigUint64LE(offset?: number): bigint
  • alias

    Buffer.readBigUInt64LE

    since

    v14.10.0, v12.19.0

    Parameters

    • Optional offset: number

    Returns bigint

  • readDoubleBE(offset?: number): number
  • Reads a 64-bit, big-endian double from buf at the specified offset.

    import { Buffer } from 'buffer';

    const buf = Buffer.from([1, 2, 3, 4, 5, 6, 7, 8]);

    console.log(buf.readDoubleBE(0));
    // Prints: 8.20788039913184e-304
    since

    v0.11.15

    Parameters

    • Optional offset: number

    Returns number

  • readDoubleLE(offset?: number): number
  • Reads a 64-bit, little-endian double from buf at the specified offset.

    import { Buffer } from 'buffer';

    const buf = Buffer.from([1, 2, 3, 4, 5, 6, 7, 8]);

    console.log(buf.readDoubleLE(0));
    // Prints: 5.447603722011605e-270
    console.log(buf.readDoubleLE(1));
    // Throws ERR_OUT_OF_RANGE.
    since

    v0.11.15

    Parameters

    • Optional offset: number

    Returns number

  • readFloatBE(offset?: number): number
  • Reads a 32-bit, big-endian float from buf at the specified offset.

    import { Buffer } from 'buffer';

    const buf = Buffer.from([1, 2, 3, 4]);

    console.log(buf.readFloatBE(0));
    // Prints: 2.387939260590663e-38
    since

    v0.11.15

    Parameters

    • Optional offset: number

    Returns number

  • readFloatLE(offset?: number): number
  • Reads a 32-bit, little-endian float from buf at the specified offset.

    import { Buffer } from 'buffer';

    const buf = Buffer.from([1, 2, 3, 4]);

    console.log(buf.readFloatLE(0));
    // Prints: 1.539989614439558e-36
    console.log(buf.readFloatLE(1));
    // Throws ERR_OUT_OF_RANGE.
    since

    v0.11.15

    Parameters

    • Optional offset: number

    Returns number

  • readInt16BE(offset?: number): number
  • 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.

    import { Buffer } from 'buffer';

    const buf = Buffer.from([0, 5]);

    console.log(buf.readInt16BE(0));
    // Prints: 5
    since

    v0.5.5

    Parameters

    • Optional offset: number

    Returns number

  • readInt16LE(offset?: number): number
  • Reads a signed, little-endian 16-bit integer from buf at the specifiedoffset.

    Integers read from a Buffer are interpreted as two's complement signed values.

    import { Buffer } from 'buffer';

    const buf = Buffer.from([0, 5]);

    console.log(buf.readInt16LE(0));
    // Prints: 1280
    console.log(buf.readInt16LE(1));
    // Throws ERR_OUT_OF_RANGE.
    since

    v0.5.5

    Parameters

    • Optional offset: number

    Returns number

  • readInt32BE(offset?: number): number
  • 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.

    import { Buffer } from 'buffer';

    const buf = Buffer.from([0, 0, 0, 5]);

    console.log(buf.readInt32BE(0));
    // Prints: 5
    since

    v0.5.5

    Parameters

    • Optional offset: number

    Returns number

  • readInt32LE(offset?: number): number
  • Reads a signed, little-endian 32-bit integer from buf at the specifiedoffset.

    Integers read from a Buffer are interpreted as two's complement signed values.

    import { Buffer } from 'buffer';

    const buf = Buffer.from([0, 0, 0, 5]);

    console.log(buf.readInt32LE(0));
    // Prints: 83886080
    console.log(buf.readInt32LE(1));
    // Throws ERR_OUT_OF_RANGE.
    since

    v0.5.5

    Parameters

    • Optional offset: number

    Returns number

  • readInt8(offset?: number): number
  • 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.

    import { Buffer } from 'buffer';

    const buf = Buffer.from([-1, 5]);

    console.log(buf.readInt8(0));
    // Prints: -1
    console.log(buf.readInt8(1));
    // Prints: 5
    console.log(buf.readInt8(2));
    // Throws ERR_OUT_OF_RANGE.
    since

    v0.5.0

    Parameters

    • Optional offset: number

    Returns number

  • readIntBE(offset: number, byteLength: number): number
  • Reads byteLength number of bytes from buf at the specified offsetand interprets the result as a big-endian, two's complement signed value supporting up to 48 bits of accuracy.

    import { Buffer } from 'buffer';

    const buf = Buffer.from([0x12, 0x34, 0x56, 0x78, 0x90, 0xab]);

    console.log(buf.readIntBE(0, 6).toString(16));
    // Prints: 1234567890ab
    console.log(buf.readIntBE(1, 6).toString(16));
    // Throws ERR_OUT_OF_RANGE.
    console.log(buf.readIntBE(1, 0).toString(16));
    // Throws ERR_OUT_OF_RANGE.
    since

    v0.11.15

    Parameters

    • offset: number

      Number of bytes to skip before starting to read. Must satisfy 0 <= offset <= buf.length - byteLength.

    • byteLength: number

      Number of bytes to read. Must satisfy 0 < byteLength <= 6.

    Returns number

  • readIntLE(offset: number, byteLength: number): number
  • Reads byteLength number of bytes from buf at the specified offsetand interprets the result as a little-endian, two's complement signed value supporting up to 48 bits of accuracy.

    import { Buffer } from 'buffer';

    const buf = Buffer.from([0x12, 0x34, 0x56, 0x78, 0x90, 0xab]);

    console.log(buf.readIntLE(0, 6).toString(16));
    // Prints: -546f87a9cbee
    since

    v0.11.15

    Parameters

    • offset: number

      Number of bytes to skip before starting to read. Must satisfy 0 <= offset <= buf.length - byteLength.

    • byteLength: number

      Number of bytes to read. Must satisfy 0 < byteLength <= 6.

    Returns number

  • readUInt16BE(offset?: number): number
  • Reads an unsigned, big-endian 16-bit integer from buf at the specifiedoffset.

    This function is also available under the readUint16BE alias.

    import { Buffer } from 'buffer';

    const buf = Buffer.from([0x12, 0x34, 0x56]);

    console.log(buf.readUInt16BE(0).toString(16));
    // Prints: 1234
    console.log(buf.readUInt16BE(1).toString(16));
    // Prints: 3456
    since

    v0.5.5

    Parameters

    • Optional offset: number

    Returns number

  • readUInt16LE(offset?: number): number
  • Reads an unsigned, little-endian 16-bit integer from buf at the specifiedoffset.

    This function is also available under the readUint16LE alias.

    import { Buffer } from 'buffer';

    const buf = Buffer.from([0x12, 0x34, 0x56]);

    console.log(buf.readUInt16LE(0).toString(16));
    // Prints: 3412
    console.log(buf.readUInt16LE(1).toString(16));
    // Prints: 5634
    console.log(buf.readUInt16LE(2).toString(16));
    // Throws ERR_OUT_OF_RANGE.
    since

    v0.5.5

    Parameters

    • Optional offset: number

    Returns number

  • readUInt32BE(offset?: number): number
  • Reads an unsigned, big-endian 32-bit integer from buf at the specifiedoffset.

    This function is also available under the readUint32BE alias.

    import { Buffer } from 'buffer';

    const buf = Buffer.from([0x12, 0x34, 0x56, 0x78]);

    console.log(buf.readUInt32BE(0).toString(16));
    // Prints: 12345678
    since

    v0.5.5

    Parameters

    • Optional offset: number

    Returns number

  • readUInt32LE(offset?: number): number
  • Reads an unsigned, little-endian 32-bit integer from buf at the specifiedoffset.

    This function is also available under the readUint32LE alias.

    import { Buffer } from 'buffer';

    const buf = Buffer.from([0x12, 0x34, 0x56, 0x78]);

    console.log(buf.readUInt32LE(0).toString(16));
    // Prints: 78563412
    console.log(buf.readUInt32LE(1).toString(16));
    // Throws ERR_OUT_OF_RANGE.
    since

    v0.5.5

    Parameters

    • Optional offset: number

    Returns number

  • readUInt8(offset?: number): number
  • Reads an unsigned 8-bit integer from buf at the specified offset.

    This function is also available under the readUint8 alias.

    import { Buffer } from 'buffer';

    const buf = Buffer.from([1, -2]);

    console.log(buf.readUInt8(0));
    // Prints: 1
    console.log(buf.readUInt8(1));
    // Prints: 254
    console.log(buf.readUInt8(2));
    // Throws ERR_OUT_OF_RANGE.
    since

    v0.5.0

    Parameters

    • Optional offset: number

    Returns number

  • readUIntBE(offset: number, byteLength: number): number
  • Reads byteLength number of bytes from buf at the specified offsetand interprets the result as an unsigned big-endian integer supporting up to 48 bits of accuracy.

    This function is also available under the readUintBE alias.

    import { Buffer } from 'buffer';

    const buf = Buffer.from([0x12, 0x34, 0x56, 0x78, 0x90, 0xab]);

    console.log(buf.readUIntBE(0, 6).toString(16));
    // Prints: 1234567890ab
    console.log(buf.readUIntBE(1, 6).toString(16));
    // Throws ERR_OUT_OF_RANGE.
    since

    v0.11.15

    Parameters

    • offset: number

      Number of bytes to skip before starting to read. Must satisfy 0 <= offset <= buf.length - byteLength.

    • byteLength: number

      Number of bytes to read. Must satisfy 0 < byteLength <= 6.

    Returns number

  • readUIntLE(offset: number, byteLength: number): number
  • Reads byteLength number of bytes from buf at the specified offsetand interprets the result as an unsigned, little-endian integer supporting up to 48 bits of accuracy.

    This function is also available under the readUintLE alias.

    import { Buffer } from 'buffer';

    const buf = Buffer.from([0x12, 0x34, 0x56, 0x78, 0x90, 0xab]);

    console.log(buf.readUIntLE(0, 6).toString(16));
    // Prints: ab9078563412
    since

    v0.11.15

    Parameters

    • offset: number

      Number of bytes to skip before starting to read. Must satisfy 0 <= offset <= buf.length - byteLength.

    • byteLength: number

      Number of bytes to read. Must satisfy 0 < byteLength <= 6.

    Returns number

  • readUint16BE(offset?: number): number
  • alias

    Buffer.readUInt16BE

    since

    v14.9.0, v12.19.0

    Parameters

    • Optional offset: number

    Returns number

  • readUint16LE(offset?: number): number
  • alias

    Buffer.readUInt16LE

    since

    v14.9.0, v12.19.0

    Parameters

    • Optional offset: number

    Returns number

  • readUint32BE(offset?: number): number
  • alias

    Buffer.readUInt32BE

    since

    v14.9.0, v12.19.0

    Parameters

    • Optional offset: number

    Returns number

  • readUint32LE(offset?: number): number
  • alias

    Buffer.readUInt32LE

    since

    v14.9.0, v12.19.0

    Parameters

    • Optional offset: number

    Returns number

  • readUint8(offset?: number): number
  • alias

    Buffer.readUInt8

    since

    v14.9.0, v12.19.0

    Parameters

    • Optional offset: number

    Returns number

  • readUintBE(offset: number, byteLength: number): number
  • alias

    Buffer.readUIntBE

    since

    v14.9.0, v12.19.0

    Parameters

    • offset: number
    • byteLength: number

    Returns number

  • readUintLE(offset: number, byteLength: number): number
  • alias

    Buffer.readUIntLE

    since

    v14.9.0, v12.19.0

    Parameters

    • offset: number
    • byteLength: number

    Returns number

  • reduce(callbackfn: ((previousValue: number, currentValue: number, currentIndex: number, array: Uint8Array) => number)): number
  • reduce(callbackfn: ((previousValue: number, currentValue: number, currentIndex: number, array: Uint8Array) => number), initialValue: number): number
  • reduce<U>(callbackfn: ((previousValue: U, currentValue: number, currentIndex: number, array: Uint8Array) => U), initialValue: U): U
  • 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.

    Parameters

    • callbackfn: ((previousValue: number, currentValue: number, currentIndex: number, array: Uint8Array) => number)

      A function that accepts up to four arguments. The reduce method calls the callbackfn function one time for each element in the array.

        • (previousValue: number, currentValue: number, currentIndex: number, array: Uint8Array): number
        • Parameters

          • previousValue: number
          • currentValue: number
          • currentIndex: number
          • array: Uint8Array

          Returns number

    Returns number

  • Parameters

    • callbackfn: ((previousValue: number, currentValue: number, currentIndex: number, array: Uint8Array) => number)
        • (previousValue: number, currentValue: number, currentIndex: number, array: Uint8Array): number
        • Parameters

          • previousValue: number
          • currentValue: number
          • currentIndex: number
          • array: Uint8Array

          Returns number

    • initialValue: number

    Returns number

  • 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.

    Type Parameters

    • U

    Parameters

    • callbackfn: ((previousValue: U, currentValue: number, currentIndex: number, array: Uint8Array) => U)

      A function that accepts up to four arguments. The reduce method calls the callbackfn function one time for each element in the array.

        • (previousValue: U, currentValue: number, currentIndex: number, array: Uint8Array): U
        • Parameters

          • previousValue: U
          • currentValue: number
          • currentIndex: number
          • array: Uint8Array

          Returns U

    • initialValue: U

      If 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.

    Returns U

  • reduceRight(callbackfn: ((previousValue: number, currentValue: number, currentIndex: number, array: Uint8Array) => number)): number
  • reduceRight(callbackfn: ((previousValue: number, currentValue: number, currentIndex: number, array: Uint8Array) => number), initialValue: number): number
  • reduceRight<U>(callbackfn: ((previousValue: U, currentValue: number, currentIndex: number, array: Uint8Array) => U), initialValue: U): U
  • 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.

    Parameters

    • callbackfn: ((previousValue: number, currentValue: number, currentIndex: number, array: Uint8Array) => number)

      A function that accepts up to four arguments. The reduceRight method calls the callbackfn function one time for each element in the array.

        • (previousValue: number, currentValue: number, currentIndex: number, array: Uint8Array): number
        • Parameters

          • previousValue: number
          • currentValue: number
          • currentIndex: number
          • array: Uint8Array

          Returns number

    Returns number

  • Parameters

    • callbackfn: ((previousValue: number, currentValue: number, currentIndex: number, array: Uint8Array) => number)
        • (previousValue: number, currentValue: number, currentIndex: number, array: Uint8Array): number
        • Parameters

          • previousValue: number
          • currentValue: number
          • currentIndex: number
          • array: Uint8Array

          Returns number

    • initialValue: number

    Returns number

  • 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.

    Type Parameters

    • U

    Parameters

    • callbackfn: ((previousValue: U, currentValue: number, currentIndex: number, array: Uint8Array) => U)

      A function that accepts up to four arguments. The reduceRight method calls the callbackfn function one time for each element in the array.

        • (previousValue: U, currentValue: number, currentIndex: number, array: Uint8Array): U
        • Parameters

          • previousValue: U
          • currentValue: number
          • currentIndex: number
          • array: Uint8Array

          Returns U

    • initialValue: U

      If 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.

    Returns U

  • Returns <internal>.Buffer

  • set(array: ArrayLike<number>, offset?: number): void
  • Sets a value or an array of values.

    Parameters

    • array: ArrayLike<number>

      A typed or untyped array of values to set.

    • Optional offset: number

      The index in the current array at which the values are to be written.

    Returns void

  • Returns a new Buffer that references the same memory as the original, but offset and cropped by the start and end indices.

    This is the same behavior as buf.subarray().

    This method is not compatible with the Uint8Array.prototype.slice(), which is a superclass of Buffer. To copy the slice, useUint8Array.prototype.slice().

    import { Buffer } from 'buffer';

    const buf = Buffer.from('buffer');

    const copiedBuf = Uint8Array.prototype.slice.call(buf);
    copiedBuf[0]++;
    console.log(copiedBuf.toString());
    // Prints: cuffer

    console.log(buf.toString());
    // Prints: buffer
    since

    v0.3.0

    Parameters

    • Optional start: number
    • Optional end: number

    Returns <internal>.Buffer

  • some(predicate: ((value: number, index: number, array: Uint8Array) => unknown), thisArg?: any): boolean
  • Determines whether the specified callback function returns true for any element of an array.

    Parameters

    • predicate: ((value: number, index: number, array: Uint8Array) => unknown)

      A function that accepts up to three arguments. The some method calls the predicate function for each element in the array until the predicate returns a value which is coercible to the Boolean value true, or until the end of the array.

        • (value: number, index: number, array: Uint8Array): unknown
        • Parameters

          • value: number
          • index: number
          • array: Uint8Array

          Returns unknown

    • Optional thisArg: any

      An object to which the this keyword can refer in the predicate function. If thisArg is omitted, undefined is used as the this value.

    Returns boolean

  • Sorts an array.

    Parameters

    • Optional compareFn: ((a: number, b: number) => number)

      Function used to determine the order of the elements. It is expected to return a negative value if first argument is less than second argument, zero if they're equal and a positive value otherwise. If omitted, the elements are sorted in ascending order.

      [11,2,22,1].sort((a, b) => a - b)
      
        • (a: number, b: number): number
        • Parameters

          • a: number
          • b: number

          Returns number

    Returns <internal>.Buffer

  • Returns a new Buffer that references the same memory as the original, but offset and cropped by the start and end indices.

    Specifying end greater than buf.length will return the same result as that of end equal to buf.length.

    This method is inherited from TypedArray.prototype.subarray().

    Modifying the new Buffer slice will modify the memory in the original Bufferbecause the allocated memory of the two objects overlap.

    import { Buffer } from 'buffer';

    // Create a `Buffer` with the ASCII alphabet, take a slice, and modify one byte
    // from the original `Buffer`.

    const buf1 = Buffer.allocUnsafe(26);

    for (let i = 0; i < 26; i++) {
    // 97 is the decimal ASCII value for 'a'.
    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

    Specifying negative indexes causes the slice to be generated relative to the end of buf rather than the beginning.

    import { Buffer } from 'buffer';

    const buf = Buffer.from('buffer');

    console.log(buf.subarray(-6, -1).toString());
    // Prints: buffe
    // (Equivalent to buf.subarray(0, 5).)

    console.log(buf.subarray(-6, -2).toString());
    // Prints: buff
    // (Equivalent to buf.subarray(0, 4).)

    console.log(buf.subarray(-5, -2).toString());
    // Prints: uff
    // (Equivalent to buf.subarray(1, 4).)
    since

    v3.0.0

    Parameters

    • Optional start: number
    • Optional end: number

    Returns <internal>.Buffer

  • Interprets buf as an array of unsigned 16-bit integers and swaps the byte order in-place. Throws ERR_INVALID_BUFFER_SIZE if buf.length is not a multiple of 2.

    import { Buffer } from 'buffer';

    const buf1 = Buffer.from([0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8]);

    console.log(buf1);
    // Prints: <Buffer 01 02 03 04 05 06 07 08>

    buf1.swap16();

    console.log(buf1);
    // Prints: <Buffer 02 01 04 03 06 05 08 07>

    const buf2 = Buffer.from([0x1, 0x2, 0x3]);

    buf2.swap16();
    // Throws ERR_INVALID_BUFFER_SIZE.

    One convenient use of buf.swap16() is to perform a fast in-place conversion between UTF-16 little-endian and UTF-16 big-endian:

    import { Buffer } from 'buffer';

    const buf = Buffer.from('This is little-endian UTF-16', 'utf16le');
    buf.swap16(); // Convert to big-endian UTF-16 text.
    since

    v5.10.0

    Returns <internal>.Buffer

    A reference to buf.

  • Interprets buf as an array of unsigned 32-bit integers and swaps the byte order in-place. Throws ERR_INVALID_BUFFER_SIZE if buf.length is not a multiple of 4.

    import { Buffer } from 'buffer';

    const buf1 = Buffer.from([0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8]);

    console.log(buf1);
    // Prints: <Buffer 01 02 03 04 05 06 07 08>

    buf1.swap32();

    console.log(buf1);
    // Prints: <Buffer 04 03 02 01 08 07 06 05>

    const buf2 = Buffer.from([0x1, 0x2, 0x3]);

    buf2.swap32();
    // Throws ERR_INVALID_BUFFER_SIZE.
    since

    v5.10.0

    Returns <internal>.Buffer

    A reference to buf.

  • Interprets buf as an array of 64-bit numbers and swaps byte order in-place. Throws ERR_INVALID_BUFFER_SIZE if buf.length is not a multiple of 8.

    import { Buffer } from 'buffer';

    const buf1 = Buffer.from([0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8]);

    console.log(buf1);
    // Prints: <Buffer 01 02 03 04 05 06 07 08>

    buf1.swap64();

    console.log(buf1);
    // Prints: <Buffer 08 07 06 05 04 03 02 01>

    const buf2 = Buffer.from([0x1, 0x2, 0x3]);

    buf2.swap64();
    // Throws ERR_INVALID_BUFFER_SIZE.
    since

    v6.3.0

    Returns <internal>.Buffer

    A reference to buf.

  • toJSON(): { data: number[]; type: "Buffer" }
  • Returns a JSON representation of buf. JSON.stringify() implicitly calls this function 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).

    import { Buffer } from 'buffer';

    const buf = Buffer.from([0x1, 0x2, 0x3, 0x4, 0x5]);
    const json = JSON.stringify(buf);

    console.log(json);
    // Prints: {"type":"Buffer","data":[1,2,3,4,5]}

    const copy = JSON.parse(json, (key, value) => {
    return value &#x26;&#x26; value.type === 'Buffer' ?
    Buffer.from(value) :
    value;
    });

    console.log(copy);
    // Prints: <Buffer 01 02 03 04 05>
    since

    v0.9.2

    Returns { data: number[]; type: "Buffer" }

    • data: number[]
    • type: "Buffer"
  • toLocaleString(): string
  • Converts a number to a string by using the current locale.

    Returns string

  • toString(encoding?: BufferEncoding, start?: number, end?: number): string
  • Decodes buf to a string according to the specified character encoding inencoding. start and end may be passed to decode only a subset of buf.

    If encoding is 'utf8' and a byte sequence in the input is not valid UTF-8, then each invalid byte is replaced with the replacement character U+FFFD.

    The maximum length of a string instance (in UTF-16 code units) is available as {@link constants.MAX_STRING_LENGTH}.

    import { Buffer } from 'buffer';

    const buf1 = Buffer.allocUnsafe(26);

    for (let i = 0; i < 26; i++) {
    // 97 is the decimal ASCII value for 'a'.
    buf1[i] = i + 97;
    }

    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
    since

    v0.1.90

    Parameters

    • Optional encoding: BufferEncoding
    • Optional start: number
    • Optional end: number

    Returns string

  • valueOf(): Uint8Array
  • Returns the primitive value of the specified object.

    Returns Uint8Array

  • Creates and returns an iterator for buf values (bytes). This function is called automatically when a Buffer is used in a for..of statement.

    import { Buffer } from 'buffer';

    const buf = Buffer.from('buffer');

    for (const value of buf.values()) {
    console.log(value);
    }
    // Prints:
    // 98
    // 117
    // 102
    // 102
    // 101
    // 114

    for (const value of buf) {
    console.log(value);
    }
    // Prints:
    // 98
    // 117
    // 102
    // 102
    // 101
    // 114
    since

    v1.1.0

    Returns IterableIterator<number>

  • write(string: string, encoding?: BufferEncoding): number
  • write(string: string, offset: number, encoding?: BufferEncoding): number
  • write(string: string, offset: number, length: number, encoding?: BufferEncoding): number
  • 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 '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
    since

    v0.1.90

    Parameters

    • string: string

      String to write to buf.

    • Optional encoding: BufferEncoding

    Returns number

    Number of bytes written.

  • Parameters

    Returns number

  • Parameters

    • string: string
    • offset: number
    • length: number
    • Optional encoding: BufferEncoding

    Returns number

  • writeBigInt64BE(value: bigint, offset?: number): number
  • Writes value to buf at the specified offset as big-endian.

    value is interpreted and written as a two's complement signed integer.

    import { Buffer } from 'buffer';

    const buf = Buffer.allocUnsafe(8);

    buf.writeBigInt64BE(0x0102030405060708n, 0);

    console.log(buf);
    // Prints: <Buffer 01 02 03 04 05 06 07 08>
    since

    v12.0.0, v10.20.0

    Parameters

    • value: bigint

      Number to be written to buf.

    • Optional offset: number

    Returns number

    offset plus the number of bytes written.

  • writeBigInt64LE(value: bigint, offset?: number): number
  • Writes value to buf at the specified offset as little-endian.

    value is interpreted and written as a two's complement signed integer.

    import { Buffer } from 'buffer';

    const buf = Buffer.allocUnsafe(8);

    buf.writeBigInt64LE(0x0102030405060708n, 0);

    console.log(buf);
    // Prints: <Buffer 08 07 06 05 04 03 02 01>
    since

    v12.0.0, v10.20.0

    Parameters

    • value: bigint

      Number to be written to buf.

    • Optional offset: number

    Returns number

    offset plus the number of bytes written.

  • writeBigUInt64BE(value: bigint, offset?: number): number
  • Writes value to buf at the specified offset as big-endian.

    This function is also available under the writeBigUint64BE alias.

    import { Buffer } from 'buffer';

    const buf = Buffer.allocUnsafe(8);

    buf.writeBigUInt64BE(0xdecafafecacefaden, 0);

    console.log(buf);
    // Prints: <Buffer de ca fa fe ca ce fa de>
    since

    v12.0.0, v10.20.0

    Parameters

    • value: bigint

      Number to be written to buf.

    • Optional offset: number

    Returns number

    offset plus the number of bytes written.

  • writeBigUInt64LE(value: bigint, offset?: number): number
  • Writes value to buf at the specified offset as little-endian

    import { Buffer } from 'buffer';

    const buf = Buffer.allocUnsafe(8);

    buf.writeBigUInt64LE(0xdecafafecacefaden, 0);

    console.log(buf);
    // Prints: <Buffer de fa ce ca fe fa ca de>

    This function is also available under the writeBigUint64LE alias.

    since

    v12.0.0, v10.20.0

    Parameters

    • value: bigint

      Number to be written to buf.

    • Optional offset: number

    Returns number

    offset plus the number of bytes written.

  • writeBigUint64BE(value: bigint, offset?: number): number
  • alias

    Buffer.writeBigUInt64BE

    since

    v14.10.0, v12.19.0

    Parameters

    • value: bigint
    • Optional offset: number

    Returns number

  • writeBigUint64LE(value: bigint, offset?: number): number
  • alias

    Buffer.writeBigUInt64LE

    since

    v14.10.0, v12.19.0

    Parameters

    • value: bigint
    • Optional offset: number

    Returns number

  • writeDoubleBE(value: number, offset?: number): number
  • Writes value to buf at the specified offset as big-endian. The valuemust be a JavaScript number. Behavior is undefined when value is anything other than a JavaScript number.

    import { Buffer } from 'buffer';

    const buf = Buffer.allocUnsafe(8);

    buf.writeDoubleBE(123.456, 0);

    console.log(buf);
    // Prints: <Buffer 40 5e dd 2f 1a 9f be 77>
    since

    v0.11.15

    Parameters

    • value: number

      Number to be written to buf.

    • Optional offset: number

    Returns number

    offset plus the number of bytes written.

  • writeDoubleLE(value: number, offset?: number): number
  • Writes value to buf at the specified offset as little-endian. The valuemust be a JavaScript number. Behavior is undefined when value is anything other than a JavaScript number.

    import { Buffer } from 'buffer';

    const buf = Buffer.allocUnsafe(8);

    buf.writeDoubleLE(123.456, 0);

    console.log(buf);
    // Prints: <Buffer 77 be 9f 1a 2f dd 5e 40>
    since

    v0.11.15

    Parameters

    • value: number

      Number to be written to buf.

    • Optional offset: number

    Returns number

    offset plus the number of bytes written.

  • writeFloatBE(value: number, offset?: number): number
  • Writes value to buf at the specified offset as big-endian. Behavior is undefined when value is anything other than a JavaScript number.

    import { Buffer } from 'buffer';

    const buf = Buffer.allocUnsafe(4);

    buf.writeFloatBE(0xcafebabe, 0);

    console.log(buf);
    // Prints: <Buffer 4f 4a fe bb>
    since

    v0.11.15

    Parameters

    • value: number

      Number to be written to buf.

    • Optional offset: number

    Returns number

    offset plus the number of bytes written.

  • writeFloatLE(value: number, offset?: number): number
  • Writes value to buf at the specified offset as little-endian. Behavior is undefined when value is anything other than a JavaScript number.

    import { Buffer } from 'buffer';

    const buf = Buffer.allocUnsafe(4);

    buf.writeFloatLE(0xcafebabe, 0);

    console.log(buf);
    // Prints: <Buffer bb fe 4a 4f>
    since

    v0.11.15

    Parameters

    • value: number

      Number to be written to buf.

    • Optional offset: number

    Returns number

    offset plus the number of bytes written.

  • writeInt16BE(value: number, offset?: number): number
  • Writes value to buf at the specified offset as big-endian. The valuemust 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.

    import { Buffer } from 'buffer';

    const buf = Buffer.allocUnsafe(2);

    buf.writeInt16BE(0x0102, 0);

    console.log(buf);
    // Prints: <Buffer 01 02>
    since

    v0.5.5

    Parameters

    • value: number

      Number to be written to buf.

    • Optional offset: number

    Returns number

    offset plus the number of bytes written.

  • writeInt16LE(value: number, offset?: number): number
  • Writes value to buf at the specified offset as little-endian. The valuemust 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.

    import { Buffer } from 'buffer';

    const buf = Buffer.allocUnsafe(2);

    buf.writeInt16LE(0x0304, 0);

    console.log(buf);
    // Prints: <Buffer 04 03>
    since

    v0.5.5

    Parameters

    • value: number

      Number to be written to buf.

    • Optional offset: number

    Returns number

    offset plus the number of bytes written.

  • writeInt32BE(value: number, offset?: number): number
  • Writes value to buf at the specified offset as big-endian. The valuemust 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.

    import { Buffer } from 'buffer';

    const buf = Buffer.allocUnsafe(4);

    buf.writeInt32BE(0x01020304, 0);

    console.log(buf);
    // Prints: <Buffer 01 02 03 04>
    since

    v0.5.5

    Parameters

    • value: number

      Number to be written to buf.

    • Optional offset: number

    Returns number

    offset plus the number of bytes written.

  • writeInt32LE(value: number, offset?: number): number
  • Writes value to buf at the specified offset as little-endian. The valuemust 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.

    import { Buffer } from 'buffer';

    const buf = Buffer.allocUnsafe(4);

    buf.writeInt32LE(0x05060708, 0);

    console.log(buf);
    // Prints: <Buffer 08 07 06 05>
    since

    v0.5.5

    Parameters

    • value: number

      Number to be written to buf.

    • Optional offset: number

    Returns number

    offset plus the number of bytes written.

  • writeInt8(value: number, offset?: number): number
  • 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.

    import { Buffer } from 'buffer';

    const buf = Buffer.allocUnsafe(2);

    buf.writeInt8(2, 0);
    buf.writeInt8(-2, 1);

    console.log(buf);
    // Prints: <Buffer 02 fe>
    since

    v0.5.0

    Parameters

    • value: number

      Number to be written to buf.

    • Optional offset: number

    Returns number

    offset plus the number of bytes written.

  • writeIntBE(value: number, offset: number, byteLength: number): number
  • Writes byteLength bytes of value to buf at the specified offsetas big-endian. Supports up to 48 bits of accuracy. Behavior is undefined whenvalue is anything other than a signed integer.

    import { Buffer } from 'buffer';

    const buf = Buffer.allocUnsafe(6);

    buf.writeIntBE(0x1234567890ab, 0, 6);

    console.log(buf);
    // Prints: <Buffer 12 34 56 78 90 ab>
    since

    v0.11.15

    Parameters

    • value: number

      Number to be written to buf.

    • offset: number

      Number of bytes to skip before starting to write. Must satisfy 0 <= offset <= buf.length - byteLength.

    • byteLength: number

      Number of bytes to write. Must satisfy 0 < byteLength <= 6.

    Returns number

    offset plus the number of bytes written.

  • writeIntLE(value: number, offset: number, byteLength: number): number
  • Writes byteLength bytes of value to buf at the specified offsetas little-endian. Supports up to 48 bits of accuracy. Behavior is undefined when value is anything other than a signed integer.

    import { Buffer } from 'buffer';

    const buf = Buffer.allocUnsafe(6);

    buf.writeIntLE(0x1234567890ab, 0, 6);

    console.log(buf);
    // Prints: <Buffer ab 90 78 56 34 12>
    since

    v0.11.15

    Parameters

    • value: number

      Number to be written to buf.

    • offset: number

      Number of bytes to skip before starting to write. Must satisfy 0 <= offset <= buf.length - byteLength.

    • byteLength: number

      Number of bytes to write. Must satisfy 0 < byteLength <= 6.

    Returns number

    offset plus the number of bytes written.

  • writeUInt16BE(value: number, offset?: number): number
  • Writes value to buf at the specified offset as big-endian. The valuemust be a valid unsigned 16-bit integer. Behavior is undefined when valueis anything other than an unsigned 16-bit integer.

    This function is also available under the writeUint16BE alias.

    import { Buffer } from 'buffer';

    const buf = Buffer.allocUnsafe(4);

    buf.writeUInt16BE(0xdead, 0);
    buf.writeUInt16BE(0xbeef, 2);

    console.log(buf);
    // Prints: <Buffer de ad be ef>
    since

    v0.5.5

    Parameters

    • value: number

      Number to be written to buf.

    • Optional offset: number

    Returns number

    offset plus the number of bytes written.

  • writeUInt16LE(value: number, offset?: number): number
  • Writes value to buf at the specified offset as little-endian. The valuemust be a valid unsigned 16-bit integer. Behavior is undefined when value is anything other than an unsigned 16-bit integer.

    This function is also available under the writeUint16LE alias.

    import { Buffer } from 'buffer';

    const buf = Buffer.allocUnsafe(4);

    buf.writeUInt16LE(0xdead, 0);
    buf.writeUInt16LE(0xbeef, 2);

    console.log(buf);
    // Prints: <Buffer ad de ef be>
    since

    v0.5.5

    Parameters

    • value: number

      Number to be written to buf.

    • Optional offset: number

    Returns number

    offset plus the number of bytes written.

  • writeUInt32BE(value: number, offset?: number): number
  • Writes value to buf at the specified offset as big-endian. The valuemust be a valid unsigned 32-bit integer. Behavior is undefined when valueis anything other than an unsigned 32-bit integer.

    This function is also available under the writeUint32BE alias.

    import { Buffer } from 'buffer';

    const buf = Buffer.allocUnsafe(4);

    buf.writeUInt32BE(0xfeedface, 0);

    console.log(buf);
    // Prints: <Buffer fe ed fa ce>
    since

    v0.5.5

    Parameters

    • value: number

      Number to be written to buf.

    • Optional offset: number

    Returns number

    offset plus the number of bytes written.

  • writeUInt32LE(value: number, offset?: number): number
  • Writes value to buf at the specified offset as little-endian. The valuemust be a valid unsigned 32-bit integer. Behavior is undefined when value is anything other than an unsigned 32-bit integer.

    This function is also available under the writeUint32LE alias.

    import { Buffer } from 'buffer';

    const buf = Buffer.allocUnsafe(4);

    buf.writeUInt32LE(0xfeedface, 0);

    console.log(buf);
    // Prints: <Buffer ce fa ed fe>
    since

    v0.5.5

    Parameters

    • value: number

      Number to be written to buf.

    • Optional offset: number

    Returns number

    offset plus the number of bytes written.

  • writeUInt8(value: number, offset?: number): number
  • 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.

    This function is also available under the writeUint8 alias.

    import { Buffer } from 'buffer';

    const buf = Buffer.allocUnsafe(4);

    buf.writeUInt8(0x3, 0);
    buf.writeUInt8(0x4, 1);
    buf.writeUInt8(0x23, 2);
    buf.writeUInt8(0x42, 3);

    console.log(buf);
    // Prints: <Buffer 03 04 23 42>
    since

    v0.5.0

    Parameters

    • value: number

      Number to be written to buf.

    • Optional offset: number

    Returns number

    offset plus the number of bytes written.

  • writeUIntBE(value: number, offset: number, byteLength: number): number
  • Writes byteLength bytes of value to buf at the specified offsetas big-endian. Supports up to 48 bits of accuracy. Behavior is undefined when value is anything other than an unsigned integer.

    This function is also available under the writeUintBE alias.

    import { Buffer } from 'buffer';

    const buf = Buffer.allocUnsafe(6);

    buf.writeUIntBE(0x1234567890ab, 0, 6);

    console.log(buf);
    // Prints: <Buffer 12 34 56 78 90 ab>
    since

    v0.5.5

    Parameters

    • value: number

      Number to be written to buf.

    • offset: number

      Number of bytes to skip before starting to write. Must satisfy 0 <= offset <= buf.length - byteLength.

    • byteLength: number

      Number of bytes to write. Must satisfy 0 < byteLength <= 6.

    Returns number

    offset plus the number of bytes written.

  • writeUIntLE(value: number, offset: number, byteLength: number): number
  • Writes byteLength bytes of value to buf at the specified offsetas little-endian. Supports up to 48 bits of accuracy. Behavior is undefined when value is anything other than an unsigned integer.

    This function is also available under the writeUintLE alias.

    import { Buffer } from 'buffer';

    const buf = Buffer.allocUnsafe(6);

    buf.writeUIntLE(0x1234567890ab, 0, 6);

    console.log(buf);
    // Prints: <Buffer ab 90 78 56 34 12>
    since

    v0.5.5

    Parameters

    • value: number

      Number to be written to buf.

    • offset: number

      Number of bytes to skip before starting to write. Must satisfy 0 <= offset <= buf.length - byteLength.

    • byteLength: number

      Number of bytes to write. Must satisfy 0 < byteLength <= 6.

    Returns number

    offset plus the number of bytes written.

  • writeUint16BE(value: number, offset?: number): number
  • alias

    Buffer.writeUInt16BE

    since

    v14.9.0, v12.19.0

    Parameters

    • value: number
    • Optional offset: number

    Returns number

  • writeUint16LE(value: number, offset?: number): number
  • alias

    Buffer.writeUInt16LE

    since

    v14.9.0, v12.19.0

    Parameters

    • value: number
    • Optional offset: number

    Returns number

  • writeUint32BE(value: number, offset?: number): number
  • alias

    Buffer.writeUInt32BE

    since

    v14.9.0, v12.19.0

    Parameters

    • value: number
    • Optional offset: number

    Returns number

  • writeUint32LE(value: number, offset?: number): number
  • alias

    Buffer.writeUInt32LE

    since

    v14.9.0, v12.19.0

    Parameters

    • value: number
    • Optional offset: number

    Returns number

  • writeUint8(value: number, offset?: number): number
  • alias

    Buffer.writeUInt8

    since

    v14.9.0, v12.19.0

    Parameters

    • value: number
    • Optional offset: number

    Returns number

  • writeUintBE(value: number, offset: number, byteLength: number): number
  • alias

    Buffer.writeUIntBE

    since

    v14.9.0, v12.19.0

    Parameters

    • value: number
    • offset: number
    • byteLength: number

    Returns number

  • writeUintLE(value: number, offset: number, byteLength: number): number
  • alias

    Buffer.writeUIntLE

    since

    v14.9.0, v12.19.0

    Parameters

    • value: number
    • offset: number
    • byteLength: number

    Returns number