--- displayed_sidebar: servicesSidebar --- import ParameterTypes from "@site/src/components/ParameterTypes" # Buffer ## Properties ## Methods #### [iterator] `**[iterator]**(): [IterableIterator](IterableIterator.mdx)<number>` ##### Returns [IterableIterator](IterableIterator.mdx)<number> ___ #### at `**at**(index): undefined \| number` Returns the item located at the specified index. ##### Parameters ##### Returns `undefined` \| `number` ___ #### compare `**compare**(target, targetStart?, targetEnd?, sourceStart?, sourceEnd?): 0 \| 1 \| -1` 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`. * `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. ```js import { Buffer } from 'node: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: [ , , ] // (This result is equal to: [buf1, buf3, buf2].) ``` The optional `targetStart`, `targetEnd`, `sourceStart`, and `sourceEnd`arguments can be used to limit the comparison to specific ranges within `target`and `buf` respectively. ```js import { Buffer } from 'node: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`. ##### Parameters ##### Returns `0` \| `1` \| `-1` #### Since v0.11.13 ___ #### copy `**copy**(target, targetStart?, sourceStart?, sourceEnd?): number` Copies data from a region of `buf` to a region in `target`, even if the `target`memory region overlaps with `buf`. [`TypedArray.prototype.set()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global\_Objects/TypedArray/set) performs the same operation, and is available for all TypedArrays, including Node.js `Buffer`s, although it takes different function arguments. ```js import { Buffer } from 'node: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!!!!!!!!!!!!! ``` ```js import { Buffer } from 'node: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 ``` ##### Parameters ##### Returns `number` #### Since v0.1.90 ___ #### copyWithin `**copyWithin**(target, start, end?): [Buffer](../index.md#buffer)` 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 ##### Returns [Buffer](../index.md#buffer) ___ #### entries `**entries**(): [IterableIterator](IterableIterator.mdx)<[number, number]>` Creates and returns an [iterator](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Iteration\_protocols) of `[index, byte]` pairs from the contents of `buf`. ```js import { Buffer } from 'node: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] ``` ##### Returns [IterableIterator](IterableIterator.mdx)<[number, number]> #### Since v1.1.0 ___ #### equals `**equals**(otherBuffer): boolean` Returns `true` if both `buf` and `otherBuffer` have exactly the same bytes,`false` otherwise. Equivalent to `buf.compare(otherBuffer) === 0`. ```js import { Buffer } from 'node: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 ``` ##### Parameters ##### Returns `boolean` #### Since v0.11.13 ___ #### every `**every**(predicate, thisArg?): boolean` Determines whether all the members of an array satisfy the specified test. ##### Parameters `unknown`", "description": "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.", "optional": false, "defaultValue": "", "expandable": false, "children": [] }, { "name": "thisArg", "type": "`any`", "description": "An object to which the this keyword can refer in the predicate function. If thisArg is omitted, undefined is used as the this value.", "optional": true, "defaultValue": "", "expandable": false, "children": [] } ]} /> ##### Returns `boolean` ___ #### fill `**fill**(value, offset?, end?, encoding?): [Buffer](../index.md#buffer)` Fills `buf` with the specified `value`. If the `offset` and `end` are not given, the entire `buf` will be filled: ```js import { Buffer } from 'node:buffer'; // Fill a `Buffer` with the ASCII character 'h'. const b = Buffer.allocUnsafe(50).fill('h'); console.log(b.toString()); // Prints: hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh // Fill a buffer with empty string const c = Buffer.allocUnsafe(5).fill(''); console.log(c.fill('')); // Prints: ``` `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`. 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: ```js import { Buffer } from 'node:buffer'; // Fill a `Buffer` with character that takes up two bytes in UTF-8. console.log(Buffer.allocUnsafe(5).fill('\u0222')); // Prints: ``` If `value` contains invalid characters, it is truncated; if no valid fill data remains, an exception is thrown: ```js import { Buffer } from 'node:buffer'; const buf = Buffer.allocUnsafe(5); console.log(buf.fill('a')); // Prints: console.log(buf.fill('aazz', 'hex')); // Prints: console.log(buf.fill('zz', 'hex')); // Throws an exception. ``` ##### Parameters ##### Returns [Buffer](../index.md#buffer) #### Since v0.5.0 ___ #### filter `**filter**(predicate, thisArg?): Uint8Array` Returns the elements of an array that meet the condition specified in a callback function. ##### Parameters `any`", "description": "A function that accepts up to three arguments. The filter method calls the predicate function one time for each element in the array.", "optional": false, "defaultValue": "", "expandable": false, "children": [] }, { "name": "thisArg", "type": "`any`", "description": "An object to which the this keyword can refer in the predicate function. If thisArg is omitted, undefined is used as the this value.", "optional": true, "defaultValue": "", "expandable": false, "children": [] } ]} /> ##### Returns Uint8Array ___ #### find `**find**(predicate, thisArg?): undefined \| number` Returns the value of the first element in the array where predicate is true, and undefined otherwise. ##### Parameters `boolean`", "description": "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.", "optional": false, "defaultValue": "", "expandable": false, "children": [] }, { "name": "thisArg", "type": "`any`", "description": "If provided, it will be used as the this value for each invocation of predicate. If it is not provided, undefined is used instead.", "optional": true, "defaultValue": "", "expandable": false, "children": [] } ]} /> ##### Returns `undefined` \| `number` ___ #### findIndex `**findIndex**(predicate, thisArg?): number` Returns the index of the first element in the array where predicate is true, and -1 otherwise. ##### Parameters `boolean`", "description": "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.", "optional": false, "defaultValue": "", "expandable": false, "children": [] }, { "name": "thisArg", "type": "`any`", "description": "If provided, it will be used as the this value for each invocation of predicate. If it is not provided, undefined is used instead.", "optional": true, "defaultValue": "", "expandable": false, "children": [] } ]} /> ##### Returns `number` ___ #### findLast `**findLast**(predicate, thisArg?): undefined \| S` Returns the value of the last element in the array where predicate is true, and undefined otherwise. ##### Type Parameters ##### Parameters value is S", "description": "findLast calls predicate once for each element of the array, in descending order, until it finds one where predicate returns true. If such an element is found, findLast immediately returns that element value. Otherwise, findLast returns undefined.", "optional": false, "defaultValue": "", "expandable": false, "children": [] }, { "name": "thisArg", "type": "`any`", "description": "If provided, it will be used as the this value for each invocation of predicate. If it is not provided, undefined is used instead.", "optional": true, "defaultValue": "", "expandable": false, "children": [] } ]} /> ##### Returns `undefined` \| `S` `**findLast**(predicate, thisArg?): undefined \| number` ##### Parameters `unknown`", "description": "", "optional": false, "defaultValue": "", "expandable": false, "children": [] }, { "name": "thisArg", "type": "`any`", "description": "", "optional": true, "defaultValue": "", "expandable": false, "children": [] } ]} /> ##### Returns `undefined` \| `number` ___ #### findLastIndex `**findLastIndex**(predicate, thisArg?): number` Returns the index of the last element in the array where predicate is true, and -1 otherwise. ##### Parameters `unknown`", "description": "findLastIndex calls predicate once for each element of the array, in descending order, until it finds one where predicate returns true. If such an element is found, findLastIndex immediately returns that element index. Otherwise, findLastIndex returns -1.", "optional": false, "defaultValue": "", "expandable": false, "children": [] }, { "name": "thisArg", "type": "`any`", "description": "If provided, it will be used as the this value for each invocation of predicate. If it is not provided, undefined is used instead.", "optional": true, "defaultValue": "", "expandable": false, "children": [] } ]} /> ##### Returns `number` ___ #### forEach `**forEach**(callbackfn, thisArg?): void` Performs the specified action for each element in an array. ##### Parameters `void`", "description": "A function that accepts up to three arguments. forEach calls the callbackfn function one time for each element in the array.", "optional": false, "defaultValue": "", "expandable": false, "children": [] }, { "name": "thisArg", "type": "`any`", "description": "An object to which the this keyword can refer in the callbackfn function. If thisArg is omitted, undefined is used as the this value.", "optional": true, "defaultValue": "", "expandable": false, "children": [] } ]} /> ##### Returns `void` ___ #### includes `**includes**(value, byteOffset?, encoding?): boolean` Equivalent to `buf.indexOf() !== -1`. ```js import { Buffer } from 'node: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 ``` ##### Parameters ##### Returns `boolean` #### Since v5.3.0 ___ #### indexOf `**indexOf**(value, byteOffset?, encoding?): number` If `value` is: * a string, `value` is interpreted according to the character encoding in`encoding`. * a `Buffer` or [`Uint8Array`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global\_Objects/Uint8Array), `value` will be used in its entirety. To compare a partial `Buffer`, use `buf.subarray`. * a number, `value` will be interpreted as an unsigned 8-bit integer value between `0` and `255`. ```js import { Buffer } from 'node: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 a`TypeError`. 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()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global\_Objects/String/indexOf). ```js import { Buffer } from 'node: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 and`byteOffset` is at least `buf.length`, `buf.length` will be returned. ##### Parameters ##### Returns `number` #### Since v1.5.0 ___ #### join `**join**(separator?): string` Adds all the elements of an array separated by the specified separator string. ##### Parameters ##### Returns `string` ___ #### keys `**keys**(): [IterableIterator](IterableIterator.mdx)<number>` Creates and returns an [iterator](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Iteration\_protocols) of `buf` keys (indices). ```js import { Buffer } from 'node:buffer'; const buf = Buffer.from('buffer'); for (const key of buf.keys()) { console.log(key); } // Prints: // 0 // 1 // 2 // 3 // 4 // 5 ``` ##### Returns [IterableIterator](IterableIterator.mdx)<number> #### Since v1.1.0 ___ #### lastIndexOf `**lastIndexOf**(value, byteOffset?, encoding?): number` Identical to `buf.indexOf()`, except the last occurrence of `value` is found rather than the first occurrence. ```js import { Buffer } from 'node: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 a`TypeError`. 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()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global\_Objects/String/lastIndexOf). ```js import { Buffer } from 'node: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. ##### Parameters ##### Returns `number` #### Since v6.0.0 ___ #### map `**map**(callbackfn, thisArg?): Uint8Array` Calls a defined callback function on each element of an array, and returns an array that contains the results. ##### Parameters `number`", "description": "A function that accepts up to three arguments. The map method calls the callbackfn function one time for each element in the array.", "optional": false, "defaultValue": "", "expandable": false, "children": [] }, { "name": "thisArg", "type": "`any`", "description": "An object to which the this keyword can refer in the callbackfn function. If thisArg is omitted, undefined is used as the this value.", "optional": true, "defaultValue": "", "expandable": false, "children": [] } ]} /> ##### Returns Uint8Array ___ #### readBigInt64BE `**readBigInt64BE**(offset?): 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. ##### Parameters ##### Returns `bigint` #### Since v12.0.0, v10.20.0 ___ #### readBigInt64LE `**readBigInt64LE**(offset?): bigint` 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. ##### Parameters ##### Returns `bigint` #### Since v12.0.0, v10.20.0 ___ #### readBigUInt64BE `**readBigUInt64BE**(offset?): bigint` Reads an unsigned, big-endian 64-bit integer from `buf` at the specified`offset`. This function is also available under the `readBigUint64BE` alias. ```js import { Buffer } from 'node:buffer'; const buf = Buffer.from([0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff]); console.log(buf.readBigUInt64BE(0)); // Prints: 4294967295n ``` ##### Parameters ##### Returns `bigint` #### Since v12.0.0, v10.20.0 ___ #### readBigUInt64LE `**readBigUInt64LE**(offset?): bigint` Reads an unsigned, little-endian 64-bit integer from `buf` at the specified`offset`. This function is also available under the `readBigUint64LE` alias. ```js import { Buffer } from 'node:buffer'; const buf = Buffer.from([0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff]); console.log(buf.readBigUInt64LE(0)); // Prints: 18446744069414584320n ``` ##### Parameters ##### Returns `bigint` #### Since v12.0.0, v10.20.0 ___ #### readBigUint64BE `**readBigUint64BE**(offset?): bigint` ##### Parameters ##### Returns `bigint` #### Alias Buffer.readBigUInt64BE #### Since v14.10.0, v12.19.0 ___ #### readBigUint64LE `**readBigUint64LE**(offset?): bigint` ##### Parameters ##### Returns `bigint` #### Alias Buffer.readBigUInt64LE #### Since v14.10.0, v12.19.0 ___ #### readDoubleBE `**readDoubleBE**(offset?): number` Reads a 64-bit, big-endian double from `buf` at the specified `offset`. ```js import { Buffer } from 'node:buffer'; const buf = Buffer.from([1, 2, 3, 4, 5, 6, 7, 8]); console.log(buf.readDoubleBE(0)); // Prints: 8.20788039913184e-304 ``` ##### Parameters ##### Returns `number` #### Since v0.11.15 ___ #### readDoubleLE `**readDoubleLE**(offset?): number` Reads a 64-bit, little-endian double from `buf` at the specified `offset`. ```js import { Buffer } from 'node: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. ``` ##### Parameters ##### Returns `number` #### Since v0.11.15 ___ #### readFloatBE `**readFloatBE**(offset?): number` Reads a 32-bit, big-endian float from `buf` at the specified `offset`. ```js import { Buffer } from 'node:buffer'; const buf = Buffer.from([1, 2, 3, 4]); console.log(buf.readFloatBE(0)); // Prints: 2.387939260590663e-38 ``` ##### Parameters ##### Returns `number` #### Since v0.11.15 ___ #### readFloatLE `**readFloatLE**(offset?): number` Reads a 32-bit, little-endian float from `buf` at the specified `offset`. ```js import { Buffer } from 'node: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. ``` ##### Parameters ##### Returns `number` #### Since v0.11.15 ___ #### readInt16BE `**readInt16BE**(offset?): 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. ```js import { Buffer } from 'node:buffer'; const buf = Buffer.from([0, 5]); console.log(buf.readInt16BE(0)); // Prints: 5 ``` ##### Parameters ##### Returns `number` #### Since v0.5.5 ___ #### readInt16LE `**readInt16LE**(offset?): number` 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. ```js import { Buffer } from 'node:buffer'; const buf = Buffer.from([0, 5]); console.log(buf.readInt16LE(0)); // Prints: 1280 console.log(buf.readInt16LE(1)); // Throws ERR_OUT_OF_RANGE. ``` ##### Parameters ##### Returns `number` #### Since v0.5.5 ___ #### readInt32BE `**readInt32BE**(offset?): 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. ```js import { Buffer } from 'node:buffer'; const buf = Buffer.from([0, 0, 0, 5]); console.log(buf.readInt32BE(0)); // Prints: 5 ``` ##### Parameters ##### Returns `number` #### Since v0.5.5 ___ #### readInt32LE `**readInt32LE**(offset?): number` 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. ```js import { Buffer } from 'node: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. ``` ##### Parameters ##### Returns `number` #### Since v0.5.5 ___ #### readInt8 `**readInt8**(offset?): 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. ```js import { Buffer } from 'node: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. ``` ##### Parameters ##### Returns `number` #### Since v0.5.0 ___ #### readIntBE `**readIntBE**(offset, byteLength): number` 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. ```js import { Buffer } from 'node: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. ``` ##### Parameters ##### Returns `number` #### Since v0.11.15 ___ #### readIntLE `**readIntLE**(offset, byteLength): number` 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. ```js import { Buffer } from 'node:buffer'; const buf = Buffer.from([0x12, 0x34, 0x56, 0x78, 0x90, 0xab]); console.log(buf.readIntLE(0, 6).toString(16)); // Prints: -546f87a9cbee ``` ##### Parameters ##### Returns `number` #### Since v0.11.15 ___ #### readUInt16BE `**readUInt16BE**(offset?): number` Reads an unsigned, big-endian 16-bit integer from `buf` at the specified`offset`. This function is also available under the `readUint16BE` alias. ```js import { Buffer } from 'node: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 ``` ##### Parameters ##### Returns `number` #### Since v0.5.5 ___ #### readUInt16LE `**readUInt16LE**(offset?): number` Reads an unsigned, little-endian 16-bit integer from `buf` at the specified`offset`. This function is also available under the `readUint16LE` alias. ```js import { Buffer } from 'node: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. ``` ##### Parameters ##### Returns `number` #### Since v0.5.5 ___ #### readUInt32BE `**readUInt32BE**(offset?): number` Reads an unsigned, big-endian 32-bit integer from `buf` at the specified`offset`. This function is also available under the `readUint32BE` alias. ```js import { Buffer } from 'node:buffer'; const buf = Buffer.from([0x12, 0x34, 0x56, 0x78]); console.log(buf.readUInt32BE(0).toString(16)); // Prints: 12345678 ``` ##### Parameters ##### Returns `number` #### Since v0.5.5 ___ #### readUInt32LE `**readUInt32LE**(offset?): number` Reads an unsigned, little-endian 32-bit integer from `buf` at the specified`offset`. This function is also available under the `readUint32LE` alias. ```js import { Buffer } from 'node: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. ``` ##### Parameters ##### Returns `number` #### Since v0.5.5 ___ #### readUInt8 `**readUInt8**(offset?): number` Reads an unsigned 8-bit integer from `buf` at the specified `offset`. This function is also available under the `readUint8` alias. ```js import { Buffer } from 'node: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. ``` ##### Parameters ##### Returns `number` #### Since v0.5.0 ___ #### readUIntBE `**readUIntBE**(offset, byteLength): number` 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. This function is also available under the `readUintBE` alias. ```js import { Buffer } from 'node: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. ``` ##### Parameters ##### Returns `number` #### Since v0.11.15 ___ #### readUIntLE `**readUIntLE**(offset, byteLength): number` Reads `byteLength` number of bytes from `buf` at the specified `offset`and 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. ```js import { Buffer } from 'node:buffer'; const buf = Buffer.from([0x12, 0x34, 0x56, 0x78, 0x90, 0xab]); console.log(buf.readUIntLE(0, 6).toString(16)); // Prints: ab9078563412 ``` ##### Parameters ##### Returns `number` #### Since v0.11.15 ___ #### readUint16BE `**readUint16BE**(offset?): number` ##### Parameters ##### Returns `number` #### Alias Buffer.readUInt16BE #### Since v14.9.0, v12.19.0 ___ #### readUint16LE `**readUint16LE**(offset?): number` ##### Parameters ##### Returns `number` #### Alias Buffer.readUInt16LE #### Since v14.9.0, v12.19.0 ___ #### readUint32BE `**readUint32BE**(offset?): number` ##### Parameters ##### Returns `number` #### Alias Buffer.readUInt32BE #### Since v14.9.0, v12.19.0 ___ #### readUint32LE `**readUint32LE**(offset?): number` ##### Parameters ##### Returns `number` #### Alias Buffer.readUInt32LE #### Since v14.9.0, v12.19.0 ___ #### readUint8 `**readUint8**(offset?): number` ##### Parameters ##### Returns `number` #### Alias Buffer.readUInt8 #### Since v14.9.0, v12.19.0 ___ #### readUintBE `**readUintBE**(offset, byteLength): number` ##### Parameters ##### Returns `number` #### Alias Buffer.readUIntBE #### Since v14.9.0, v12.19.0 ___ #### readUintLE `**readUintLE**(offset, byteLength): number` ##### Parameters ##### Returns `number` #### Alias Buffer.readUIntLE #### Since v14.9.0, v12.19.0 ___ #### reduce `**reduce**(callbackfn): 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. ##### Parameters `number`", "description": "A function that accepts up to four arguments. The reduce method calls the callbackfn function one time for each element in the array.", "optional": false, "defaultValue": "", "expandable": false, "children": [] } ]} /> ##### Returns `number` `**reduce**(callbackfn, initialValue): number` ##### Parameters `number`", "description": "", "optional": false, "defaultValue": "", "expandable": false, "children": [] }, { "name": "initialValue", "type": "`number`", "description": "", "optional": false, "defaultValue": "", "expandable": false, "children": [] } ]} /> ##### Returns `number` `**reduce**(callbackfn, initialValue): 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. ##### Type Parameters ##### Parameters `U`", "description": "A function that accepts up to four arguments. The reduce method calls the callbackfn function one time for each element in the array.", "optional": false, "defaultValue": "", "expandable": false, "children": [] }, { "name": "initialValue", "type": "`U`", "description": "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.", "optional": false, "defaultValue": "", "expandable": false, "children": [] } ]} /> ##### Returns `U` ___ #### reduceRight `**reduceRight**(callbackfn): 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. ##### Parameters `number`", "description": "A function that accepts up to four arguments. The reduceRight method calls the callbackfn function one time for each element in the array.", "optional": false, "defaultValue": "", "expandable": false, "children": [] } ]} /> ##### Returns `number` `**reduceRight**(callbackfn, initialValue): number` ##### Parameters `number`", "description": "", "optional": false, "defaultValue": "", "expandable": false, "children": [] }, { "name": "initialValue", "type": "`number`", "description": "", "optional": false, "defaultValue": "", "expandable": false, "children": [] } ]} /> ##### Returns `number` `**reduceRight**(callbackfn, initialValue): 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. ##### Type Parameters ##### Parameters `U`", "description": "A function that accepts up to four arguments. The reduceRight method calls the callbackfn function one time for each element in the array.", "optional": false, "defaultValue": "", "expandable": false, "children": [] }, { "name": "initialValue", "type": "`U`", "description": "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.", "optional": false, "defaultValue": "", "expandable": false, "children": [] } ]} /> ##### Returns `U` ___ #### reverse `**reverse**(): [Buffer](../index.md#buffer)` ##### Returns [Buffer](../index.md#buffer) ___ #### set `**set**(array, offset?): void` Sets a value or an array of values. ##### Parameters ##### Returns `void` ___ #### slice `**slice**(start?, end?): [Buffer](../index.md#buffer)` Returns a new `Buffer` that references the same memory as the original, but offset and cropped by the `start` and `end` indices. This method is not compatible with the `Uint8Array.prototype.slice()`, which is a superclass of `Buffer`. To copy the slice, use`Uint8Array.prototype.slice()`. ```js import { Buffer } from 'node: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 // With buf.slice(), the original buffer is modified. const notReallyCopiedBuf = buf.slice(); notReallyCopiedBuf[0]++; console.log(notReallyCopiedBuf.toString()); // Prints: cuffer console.log(buf.toString()); // Also prints: cuffer (!) ``` ##### Parameters ##### Returns [Buffer](../index.md#buffer) #### Since v0.3.0 #### Deprecated Use `subarray` instead. ___ #### some `**some**(predicate, thisArg?): boolean` Determines whether the specified callback function returns true for any element of an array. ##### Parameters `unknown`", "description": "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.", "optional": false, "defaultValue": "", "expandable": false, "children": [] }, { "name": "thisArg", "type": "`any`", "description": "An object to which the this keyword can refer in the predicate function. If thisArg is omitted, undefined is used as the this value.", "optional": true, "defaultValue": "", "expandable": false, "children": [] } ]} /> ##### Returns `boolean` ___ #### sort `**sort**(compareFn?): [Buffer](../index.md#buffer)` Sorts an array. ##### Parameters `number`", "description": "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. ```ts [11,2,22,1].sort((a, b) => a - b) ```", "optional": true, "defaultValue": "", "expandable": false, "children": [] } ]} /> ##### Returns [Buffer](../index.md#buffer) ___ #### subarray `**subarray**(start?, end?): [Buffer](../index.md#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()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global\_Objects/TypedArray/subarray). Modifying the new `Buffer` slice will modify the memory in the original `Buffer`because the allocated memory of the two objects overlap. ```js import { Buffer } from 'node: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. ```js import { Buffer } from 'node: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).) ``` ##### Parameters ##### Returns [Buffer](../index.md#buffer) #### Since v3.0.0 ___ #### swap16 `**swap16**(): [Buffer](../index.md#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. ```js import { Buffer } from 'node:buffer'; const buf1 = Buffer.from([0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8]); console.log(buf1); // Prints: buf1.swap16(); console.log(buf1); // Prints: 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: ```js import { Buffer } from 'node:buffer'; const buf = Buffer.from('This is little-endian UTF-16', 'utf16le'); buf.swap16(); // Convert to big-endian UTF-16 text. ``` ##### Returns [Buffer](../index.md#buffer) #### Since v5.10.0 ___ #### swap32 `**swap32**(): [Buffer](../index.md#buffer)` 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. ```js import { Buffer } from 'node:buffer'; const buf1 = Buffer.from([0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8]); console.log(buf1); // Prints: buf1.swap32(); console.log(buf1); // Prints: const buf2 = Buffer.from([0x1, 0x2, 0x3]); buf2.swap32(); // Throws ERR_INVALID_BUFFER_SIZE. ``` ##### Returns [Buffer](../index.md#buffer) #### Since v5.10.0 ___ #### swap64 `**swap64**(): [Buffer](../index.md#buffer)` 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. ```js import { Buffer } from 'node:buffer'; const buf1 = Buffer.from([0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8]); console.log(buf1); // Prints: buf1.swap64(); console.log(buf1); // Prints: const buf2 = Buffer.from([0x1, 0x2, 0x3]); buf2.swap64(); // Throws ERR_INVALID_BUFFER_SIZE. ``` ##### Returns [Buffer](../index.md#buffer) #### Since v6.3.0 ___ #### toJSON `**toJSON**(): { data: number[] ; type: "Buffer" }` Returns a JSON representation of `buf`. [`JSON.stringify()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global\_Objects/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)`. ```js import { Buffer } from 'node: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 && value.type === 'Buffer' ? Buffer.from(value) : value; }); console.log(copy); // Prints: ``` ##### Returns `object` #### Since v0.9.2 ___ #### toLocaleString `**toLocaleString**(): string` Converts a number to a string by using the current locale. ##### Returns `string` ___ #### toReversed `**toReversed**(): Uint8Array` Copies the array and returns the copy with the elements in reverse order. ##### Returns Uint8Array ___ #### toSorted `**toSorted**(compareFn?): Uint8Array` Copies and sorts the array. ##### Parameters `number`", "description": "Function used to determine the order of the elements. It is expected to return a negative value if the first argument is less than the second argument, zero if they're equal, and a positive value otherwise. If omitted, the elements are sorted in ascending, ASCII character order. ```ts const myNums = Uint8Array.from([11, 2, 22, 1]); myNums.toSorted((a, b) => a - b) // Uint8Array(4) [1, 2, 11, 22] ```", "optional": true, "defaultValue": "", "expandable": false, "children": [] } ]} /> ##### Returns Uint8Array ___ #### toString `**toString**(encoding?, start?, end?): string` 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`. 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 constants.MAX_STRING_LENGTH. ```js import { Buffer } from 'node: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 ``` ##### Parameters ##### Returns `string` #### Since v0.1.90 ___ #### valueOf `**valueOf**(): Uint8Array` Returns the primitive value of the specified object. ##### Returns Uint8Array ___ #### values `**values**(): [IterableIterator](IterableIterator.mdx)<number>` Creates and returns an [iterator](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Iteration\_protocols) for `buf` values (bytes). This function is called automatically when a `Buffer` is used in a `for..of` statement. ```js import { Buffer } from 'node: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 ``` ##### Returns [IterableIterator](IterableIterator.mdx)<number> #### Since v1.1.0 ___ #### with `**with**(index, value): Uint8Array` Copies the array and inserts the given number at the provided index. ##### Parameters ##### Returns Uint8Array ___ #### write `**write**(string, encoding?): number` 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. ```js 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 ``` ##### Parameters ##### Returns `number` #### Since v0.1.90 `**write**(string, offset, encoding?): number` ##### Parameters ##### Returns `number` `**write**(string, offset, length, encoding?): number` ##### Parameters ##### Returns `number` ___ #### writeBigInt64BE `**writeBigInt64BE**(value, offset?): number` Writes `value` to `buf` at the specified `offset` as big-endian. `value` is interpreted and written as a two's complement signed integer. ```js import { Buffer } from 'node:buffer'; const buf = Buffer.allocUnsafe(8); buf.writeBigInt64BE(0x0102030405060708n, 0); console.log(buf); // Prints: ``` ##### Parameters ##### Returns `number` #### Since v12.0.0, v10.20.0 ___ #### writeBigInt64LE `**writeBigInt64LE**(value, offset?): number` Writes `value` to `buf` at the specified `offset` as little-endian. `value` is interpreted and written as a two's complement signed integer. ```js import { Buffer } from 'node:buffer'; const buf = Buffer.allocUnsafe(8); buf.writeBigInt64LE(0x0102030405060708n, 0); console.log(buf); // Prints: ``` ##### Parameters ##### Returns `number` #### Since v12.0.0, v10.20.0 ___ #### writeBigUInt64BE `**writeBigUInt64BE**(value, offset?): number` Writes `value` to `buf` at the specified `offset` as big-endian. This function is also available under the `writeBigUint64BE` alias. ```js import { Buffer } from 'node:buffer'; const buf = Buffer.allocUnsafe(8); buf.writeBigUInt64BE(0xdecafafecacefaden, 0); console.log(buf); // Prints: ``` ##### Parameters ##### Returns `number` #### Since v12.0.0, v10.20.0 ___ #### writeBigUInt64LE `**writeBigUInt64LE**(value, offset?): number` Writes `value` to `buf` at the specified `offset` as little-endian ```js import { Buffer } from 'node:buffer'; const buf = Buffer.allocUnsafe(8); buf.writeBigUInt64LE(0xdecafafecacefaden, 0); console.log(buf); // Prints: ``` This function is also available under the `writeBigUint64LE` alias. ##### Parameters ##### Returns `number` #### Since v12.0.0, v10.20.0 ___ #### writeBigUint64BE `**writeBigUint64BE**(value, offset?): number` ##### Parameters ##### Returns `number` #### Alias Buffer.writeBigUInt64BE #### Since v14.10.0, v12.19.0 ___ #### writeBigUint64LE `**writeBigUint64LE**(value, offset?): number` ##### Parameters ##### Returns `number` #### Alias Buffer.writeBigUInt64LE #### Since v14.10.0, v12.19.0 ___ #### writeDoubleBE `**writeDoubleBE**(value, offset?): number` 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. ```js import { Buffer } from 'node:buffer'; const buf = Buffer.allocUnsafe(8); buf.writeDoubleBE(123.456, 0); console.log(buf); // Prints: ``` ##### Parameters ##### Returns `number` #### Since v0.11.15 ___ #### writeDoubleLE `**writeDoubleLE**(value, offset?): number` 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. ```js import { Buffer } from 'node:buffer'; const buf = Buffer.allocUnsafe(8); buf.writeDoubleLE(123.456, 0); console.log(buf); // Prints: ``` ##### Parameters ##### Returns `number` #### Since v0.11.15 ___ #### writeFloatBE `**writeFloatBE**(value, offset?): number` Writes `value` to `buf` at the specified `offset` as big-endian. Behavior is undefined when `value` is anything other than a JavaScript number. ```js import { Buffer } from 'node:buffer'; const buf = Buffer.allocUnsafe(4); buf.writeFloatBE(0xcafebabe, 0); console.log(buf); // Prints: ``` ##### Parameters ##### Returns `number` #### Since v0.11.15 ___ #### writeFloatLE `**writeFloatLE**(value, offset?): number` Writes `value` to `buf` at the specified `offset` as little-endian. Behavior is undefined when `value` is anything other than a JavaScript number. ```js import { Buffer } from 'node:buffer'; const buf = Buffer.allocUnsafe(4); buf.writeFloatLE(0xcafebabe, 0); console.log(buf); // Prints: ``` ##### Parameters ##### Returns `number` #### Since v0.11.15 ___ #### writeInt16BE `**writeInt16BE**(value, offset?): number` 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. ```js import { Buffer } from 'node:buffer'; const buf = Buffer.allocUnsafe(2); buf.writeInt16BE(0x0102, 0); console.log(buf); // Prints: ``` ##### Parameters ##### Returns `number` #### Since v0.5.5 ___ #### writeInt16LE `**writeInt16LE**(value, offset?): number` 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. ```js import { Buffer } from 'node:buffer'; const buf = Buffer.allocUnsafe(2); buf.writeInt16LE(0x0304, 0); console.log(buf); // Prints: ``` ##### Parameters ##### Returns `number` #### Since v0.5.5 ___ #### writeInt32BE `**writeInt32BE**(value, offset?): number` 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. ```js import { Buffer } from 'node:buffer'; const buf = Buffer.allocUnsafe(4); buf.writeInt32BE(0x01020304, 0); console.log(buf); // Prints: ``` ##### Parameters ##### Returns `number` #### Since v0.5.5 ___ #### writeInt32LE `**writeInt32LE**(value, offset?): number` 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. ```js import { Buffer } from 'node:buffer'; const buf = Buffer.allocUnsafe(4); buf.writeInt32LE(0x05060708, 0); console.log(buf); // Prints: ``` ##### Parameters ##### Returns `number` #### Since v0.5.5 ___ #### writeInt8 `**writeInt8**(value, offset?): 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. ```js import { Buffer } from 'node:buffer'; const buf = Buffer.allocUnsafe(2); buf.writeInt8(2, 0); buf.writeInt8(-2, 1); console.log(buf); // Prints: ``` ##### Parameters ##### Returns `number` #### Since v0.5.0 ___ #### writeIntBE `**writeIntBE**(value, offset, byteLength): number` 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. ```js import { Buffer } from 'node:buffer'; const buf = Buffer.allocUnsafe(6); buf.writeIntBE(0x1234567890ab, 0, 6); console.log(buf); // Prints: ``` ##### Parameters ##### Returns `number` #### Since v0.11.15 ___ #### writeIntLE `**writeIntLE**(value, offset, byteLength): number` 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. ```js import { Buffer } from 'node:buffer'; const buf = Buffer.allocUnsafe(6); buf.writeIntLE(0x1234567890ab, 0, 6); console.log(buf); // Prints: ``` ##### Parameters ##### Returns `number` #### Since v0.11.15 ___ #### writeUInt16BE `**writeUInt16BE**(value, offset?): number` 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. This function is also available under the `writeUint16BE` alias. ```js import { Buffer } from 'node:buffer'; const buf = Buffer.allocUnsafe(4); buf.writeUInt16BE(0xdead, 0); buf.writeUInt16BE(0xbeef, 2); console.log(buf); // Prints: ``` ##### Parameters ##### Returns `number` #### Since v0.5.5 ___ #### writeUInt16LE `**writeUInt16LE**(value, offset?): number` 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. This function is also available under the `writeUint16LE` alias. ```js import { Buffer } from 'node:buffer'; const buf = Buffer.allocUnsafe(4); buf.writeUInt16LE(0xdead, 0); buf.writeUInt16LE(0xbeef, 2); console.log(buf); // Prints: ``` ##### Parameters ##### Returns `number` #### Since v0.5.5 ___ #### writeUInt32BE `**writeUInt32BE**(value, offset?): number` 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. This function is also available under the `writeUint32BE` alias. ```js import { Buffer } from 'node:buffer'; const buf = Buffer.allocUnsafe(4); buf.writeUInt32BE(0xfeedface, 0); console.log(buf); // Prints: ``` ##### Parameters ##### Returns `number` #### Since v0.5.5 ___ #### writeUInt32LE `**writeUInt32LE**(value, offset?): number` 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. This function is also available under the `writeUint32LE` alias. ```js import { Buffer } from 'node:buffer'; const buf = Buffer.allocUnsafe(4); buf.writeUInt32LE(0xfeedface, 0); console.log(buf); // Prints: ``` ##### Parameters ##### Returns `number` #### Since v0.5.5 ___ #### writeUInt8 `**writeUInt8**(value, offset?): 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. ```js import { Buffer } from 'node: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: ``` ##### Parameters ##### Returns `number` #### Since v0.5.0 ___ #### writeUIntBE `**writeUIntBE**(value, offset, byteLength): number` 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. This function is also available under the `writeUintBE` alias. ```js import { Buffer } from 'node:buffer'; const buf = Buffer.allocUnsafe(6); buf.writeUIntBE(0x1234567890ab, 0, 6); console.log(buf); // Prints: ``` ##### Parameters ##### Returns `number` #### Since v0.5.5 ___ #### writeUIntLE `**writeUIntLE**(value, offset, byteLength): number` 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. This function is also available under the `writeUintLE` alias. ```js import { Buffer } from 'node:buffer'; const buf = Buffer.allocUnsafe(6); buf.writeUIntLE(0x1234567890ab, 0, 6); console.log(buf); // Prints: ``` ##### Parameters ##### Returns `number` #### Since v0.5.5 ___ #### writeUint16BE `**writeUint16BE**(value, offset?): number` ##### Parameters ##### Returns `number` #### Alias Buffer.writeUInt16BE #### Since v14.9.0, v12.19.0 ___ #### writeUint16LE `**writeUint16LE**(value, offset?): number` ##### Parameters ##### Returns `number` #### Alias Buffer.writeUInt16LE #### Since v14.9.0, v12.19.0 ___ #### writeUint32BE `**writeUint32BE**(value, offset?): number` ##### Parameters ##### Returns `number` #### Alias Buffer.writeUInt32BE #### Since v14.9.0, v12.19.0 ___ #### writeUint32LE `**writeUint32LE**(value, offset?): number` ##### Parameters ##### Returns `number` #### Alias Buffer.writeUInt32LE #### Since v14.9.0, v12.19.0 ___ #### writeUint8 `**writeUint8**(value, offset?): number` ##### Parameters ##### Returns `number` #### Alias Buffer.writeUInt8 #### Since v14.9.0, v12.19.0 ___ #### writeUintBE `**writeUintBE**(value, offset, byteLength): number` ##### Parameters ##### Returns `number` #### Alias Buffer.writeUIntBE #### Since v14.9.0, v12.19.0 ___ #### writeUintLE `**writeUintLE**(value, offset, byteLength): number` ##### Parameters ##### Returns `number` #### Alias Buffer.writeUIntLE #### Since v14.9.0, v12.19.0