---
title: BigUint64Array
slug: Web/JavaScript/Reference/Global_Objects/BigUint64Array
translation_of: Web/JavaScript/Reference/Global_Objects/BigUint64Array
---
<div> {{JSRef}}</div>

<p><strong><code>BigUint64Array</code></strong> 类型数组表示一个平台字节顺序的64位无符号整型数组。如果想要控制字符顺序，请使用 {{jsxref("DataView")}} 替代。内容初始化为 <code>0n</code>. 创建之后可以使用对象中的方法或使用标准数组索引语法(括号表示法)来获取数组中的元素。</p>

<h2 id="句法">句法</h2>

<pre class="syntaxbox">new BigUint64Array();
new BigUint64Array(length);
new BigUint64Array(typedArray);
new BigUint64Array(object);
new BigUint64Array(buffer [, byteOffset [, length]]);</pre>

<p>更多有关构造方法和参数的信息，参见 <em><a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray#Syntax">TypedArray</a></em>.</p>

<h2 id="属性">属性</h2>

<dl>
 <dt>{{jsxref("TypedArray.BYTES_PER_ELEMENT", "BigUint64Array.BYTES_PER_ELEMENT")}}</dt>
 <dd>返回一个元素容量的数字值. <code>8</code> in the case of a <code>BigUint64Array</code>.</dd>
 <dt>BigUint64Array.length</dt>
 <dd>Static length property whose value is 3. For the actual length (number of elements), see {{jsxref("TypedArray.prototype.length", "BigUint64Array.prototype.length")}}.</dd>
 <dt>{{jsxref("TypedArray.name", "BigUint64Array.name")}}</dt>
 <dd>Returns the string value of the constructor name. In the case of the <code>BigUint64Array</code> type: "BigUint64Array".</dd>
 <dt>{{jsxref("TypedArray.prototype", "BigUint64Array.prototype")}}</dt>
 <dd>Prototype for the <em>TypedArray</em> objects.</dd>
</dl>

<h2 id="Methods">Methods</h2>

<dl>
 <dt>{{jsxref("TypedArray.from", "BigUint64Array.from()")}}</dt>
 <dd>Creates a new <code>BigUint64Array</code> from an array-like or iterable object. See also {{jsxref("Array.from()")}}.</dd>
 <dt>{{jsxref("TypedArray.of", "BigUint64Array.of()")}}</dt>
 <dd>Creates a new <code>BigUint64Array</code> with a variable number of arguments. See also {{jsxref("Array.of()")}}.</dd>
</dl>

<h2 id="BigUint64Array_prototype"><code>BigUint64Array</code> prototype</h2>

<p>All <code>BigUint64Array</code> objects inherit from {{jsxref("TypedArray.prototype", "%TypedArray%.prototype")}}.</p>

<h3 id="Properties">Properties</h3>

<dl>
 <dt><code>BigUint64Array.prototype.constructor</code></dt>
 <dd>Returns the function that created an instance's prototype. This is the <code>BigUint64Array</code> constructor by default.</dd>
 <dt>{{jsxref("TypedArray.prototype.buffer", "BigUint64Array.prototype.buffer")}} {{readonlyInline}}</dt>
 <dd>Returns the {{jsxref("ArrayBuffer")}} referenced by the <code>BigUint64Array</code>. Fixed at construction time and thus <strong>read only</strong>.</dd>
 <dt>{{jsxref("TypedArray.prototype.byteLength", "BigUint64Array.prototype.byteLength")}} {{readonlyInline}}</dt>
 <dd>Returns the length (in bytes) of the <code>BigUint64Array</code> from the start of its {{jsxref("ArrayBuffer")}}. Fixed at construction time and thus <strong>read only.</strong></dd>
 <dt>{{jsxref("TypedArray.prototype.byteOffset", "BigUint64Array.prototype.byteOffset")}} {{readonlyInline}}</dt>
 <dd>Returns the offset (in bytes) of the <code>BigUint64Array</code> from the start of its {{jsxref("ArrayBuffer")}}. Fixed at construction time and thus <strong>read only.</strong></dd>
 <dt>{{jsxref("TypedArray.prototype.length", "BigUint64Array.prototype.length")}} {{readonlyInline}}</dt>
 <dd>Returns the number of elements hold in the <code>BigUint64Array</code>. Fixed at construction time and thus <strong>read only.</strong></dd>
</dl>

<h3 id="Methods_2">Methods</h3>

<dl>
 <dt>{{jsxref("TypedArray.copyWithin", "BigUint64Array.prototype.copyWithin()")}}</dt>
 <dd>Copies a sequence of array elements within the array. See also {{jsxref("Array.prototype.copyWithin()")}}.</dd>
 <dt>{{jsxref("TypedArray.entries", "BigUint64Array.prototype.entries()")}}</dt>
 <dd>Returns a new <code>Array Iterator</code> object that contains the key/value pairs for each index in the array. See also {{jsxref("Array.prototype.entries()")}}.</dd>
 <dt>{{jsxref("TypedArray.every", "BigUint64Array.prototype.every()")}}</dt>
 <dd>Tests whether all elements in the array pass the test provided by a function. See also {{jsxref("Array.prototype.every()")}}.</dd>
 <dt>{{jsxref("TypedArray.fill", "BigUint64Array.prototype.fill()")}}</dt>
 <dd>Fills all the elements of an array from a start index to an end index with a static value. See also {{jsxref("Array.prototype.fill()")}}.</dd>
 <dt>{{jsxref("TypedArray.filter", "BigUint64Array.prototype.filter()")}}</dt>
 <dd>Creates a new array with all of the elements of this array for which the provided filtering function returns true. See also {{jsxref("Array.prototype.filter()")}}.</dd>
 <dt>{{jsxref("TypedArray.find", "BigUint64Array.prototype.find()")}}</dt>
 <dd>Returns the found value in the array, if an element in the array satisfies the provided testing function or <code>undefined</code> if not found. See also {{jsxref("Array.prototype.find()")}}.</dd>
 <dt>{{jsxref("TypedArray.findIndex", "BigUint64Array.prototype.findIndex()")}}</dt>
 <dd>Returns the found index in the array, if an element in the array satisfies the provided testing function or -1 if not found. See also {{jsxref("Array.prototype.findIndex()")}}.</dd>
 <dt>{{jsxref("TypedArray.forEach", "BigUint64Array.prototype.forEach()")}}</dt>
 <dd>Calls a function for each element in the array. See also {{jsxref("Array.prototype.forEach()")}}.</dd>
 <dt>{{jsxref("TypedArray.includes", "BigUint64Array.prototype.includes()")}}</dt>
 <dd>Determines whether a typed array includes a certain element, returning <code>true</code> or <code>false</code> as appropriate. See also {{jsxref("Array.prototype.includes()")}}.</dd>
 <dt>{{jsxref("TypedArray.indexOf", "BigUint64Array.prototype.indexOf()")}}</dt>
 <dd>Returns the first (least) index of an element within the array equal to the specified value, or -1 if none is found. See also {{jsxref("Array.prototype.indexOf()")}}.</dd>
 <dt>{{jsxref("TypedArray.join", "BigUint64Array.prototype.join()")}}</dt>
 <dd>Joins all elements of an array into a string. See also {{jsxref("Array.prototype.join()")}}.</dd>
 <dt>{{jsxref("TypedArray.keys", "BigUint64Array.prototype.keys()")}}</dt>
 <dd>Returns a new <code>Array Iterator</code> that contains the keys for each index in the array. See also {{jsxref("Array.prototype.keys()")}}.</dd>
 <dt>{{jsxref("TypedArray.lastIndexOf", "BigUint64Array.prototype.lastIndexOf()")}}</dt>
 <dd>Returns the last (greatest) index of an element within the array equal to the specified value, or -1 if none is found. See also {{jsxref("Array.prototype.lastIndexOf()")}}.</dd>
 <dt>{{jsxref("TypedArray.map", "BigUint64Array.prototype.map()")}}</dt>
 <dd>Creates a new array with the results of calling a provided function on every element in this array. See also {{jsxref("Array.prototype.map()")}}.</dd>
 <dt>{{jsxref("TypedArray.reduce", "BigUint64Array.prototype.reduce()")}}</dt>
 <dd>Apply a function against an accumulator and each value of the array (from left-to-right) as to reduce it to a single value. See also {{jsxref("Array.prototype.reduce()")}}.</dd>
 <dt>{{jsxref("TypedArray.reduceRight", "BigUint64Array.prototype.reduceRight()")}}</dt>
 <dd>Apply a function against an accumulator and each value of the array (from right-to-left) as to reduce it to a single value. See also {{jsxref("Array.prototype.reduceRight()")}}.</dd>
 <dt>{{jsxref("TypedArray.reverse", "BigUint64Array.prototype.reverse()")}}</dt>
 <dd>Reverses the order of the elements of an array — the first becomes the last, and the last becomes the first. See also {{jsxref("Array.prototype.reverse()")}}.</dd>
 <dt>{{jsxref("TypedArray.set", "BigUint64Array.prototype.set()")}}</dt>
 <dd>Stores multiple values in the typed array, reading input values from a specified array.</dd>
 <dt>{{jsxref("TypedArray.slice", "BigUint64Array.prototype.slice()")}}</dt>
 <dd>Extracts a section of an array and returns a new array. See also {{jsxref("Array.prototype.slice()")}}.</dd>
 <dt>{{jsxref("TypedArray.some", "BigUint64Array.prototype.some()")}}</dt>
 <dd>Returns true if at least one element in this array satisfies the provided testing function. See also {{jsxref("Array.prototype.some()")}}.</dd>
 <dt>{{jsxref("TypedArray.sort", "BigUint64Array.prototype.sort()")}}</dt>
 <dd>Sorts the elements of an array in place and returns the array. See also {{jsxref("Array.prototype.sort()")}}.</dd>
 <dt>{{jsxref("TypedArray.subarray", "BigUint64Array.prototype.subarray()")}}</dt>
 <dd>Returns a new <code>BigUint64Array</code> from the given start and end element index.</dd>
 <dt>{{jsxref("TypedArray.values", "BigUint64Array.prototype.values()")}}</dt>
 <dd>Returns a new <code>Array Iterator</code> object that contains the values for each index in the array. See also {{jsxref("Array.prototype.values()")}}.</dd>
 <dt>{{jsxref("TypedArray.toLocaleString", "BigUint64Array.prototype.toLocaleString()")}}</dt>
 <dd>Returns a localized string representing the array and its elements. See also {{jsxref("Array.prototype.toLocaleString()")}}.</dd>
 <dt>{{jsxref("TypedArray.toString", "BigUint64Array.prototype.toString()")}}</dt>
 <dd>Returns a string representing the array and its elements. See also {{jsxref("Array.prototype.toString()")}}.</dd>
 <dt>{{jsxref("TypedArray.@@iterator", "BigUint64Array.prototype[@@iterator]()")}}</dt>
 <dd>Returns a new <code>Array Iterator</code> object that contains the values for each index in the array.</dd>
</dl>

<h2 id="Examples">Examples</h2>

<p>Different ways to create a <code>BigUint64Array</code>:</p>

<pre class="brush: js">// From a length
var biguint64 = new BigUint64Array(2);
biguint64[0] = 42n;
console.log(biguint64[0]); // 42n
console.log(biguint64.length); // 2
console.log(biguint64.BYTES_PER_ELEMENT); // 8

// From an array
var arr = new BigUint64Array([21n,31n]);
console.log(arr[1]); // 31n

// From another TypedArray
var x = new BigUint64Array([21n, 31n]);
var y = new BigUint64Array(x);
console.log(y[0]); // 21n

// From an ArrayBuffer
var buffer = new ArrayBuffer(32);
var z = new BigUint64Array(buffer, 0, 4);

// From an iterable
var iterable = function*(){ yield* [1n, 2n, 3n]; }();
var biguint64 = new BigUint64Array(iterable);
// BigUint64Array[1n, 2n, 3n]
</pre>

<h2 id="Specifications">Specifications</h2>

<p><a href="https://tc39.github.io/proposal-bigint/#sec-typedarrays-and-dataview">BigInt proposal</a></p>

<h2 id="Browser_compatibility">Browser compatibility</h2>



<p>{{Compat("javascript.builtins.BigUint64Array")}}</p>

<h2 id="See_also">See also</h2>

<ul>
 <li><a href="/en-US/docs/Web/JavaScript/Typed_arrays" title="en/JavaScript typed arrays">JavaScript typed arrays</a></li>
 <li>{{jsxref("BigInt64Array")}}</li>
 <li>{{jsxref("DataView")}}</li>
</ul>