BigUint64Array() constructor

The BigUint64Array() typed array constructor creates a new BigUint64Array object, which is, an array of 64-bit unsigned integers in the platform byte order. If control over byte order is needed, use DataView instead. The contents are initialized to 0n. Once established, you can reference elements in the array using the object's methods, or by using standard array index syntax (that is, using bracket notation).

Syntax

new BigUint64Array();
new BigUint64Array(length);
new BigUint64Array(typedArray);
new BigUint64Array(object);

new BigUint64Array(buffer);
new BigUint64Array(buffer, byteOffset);
new BigUint64Array(buffer, byteOffset, length);

Parameters

length

When called with a length argument, an internal array buffer is created in memory, of size length multiplied by BYTES_PER_ELEMENT bytes, containing zeros.

typedArray

When called with a typedArray argument, which can be an object of any of the typed array types (such as Int32Array), the typedArray gets copied into a new typed array. Each value in typedArray is converted to the corresponding type of the constructor before being copied into the new array. The length of the new typed array will be same as the length of the typedArray argument.

object

When called with an object argument, a new typed array is created as if by the TypedArray.from() method.

buffer, byteOffset, length

When called with a buffer, and optionally a byteOffset and a length argument, a new typed array view is created that views the specified ArrayBuffer. The byteOffset and length parameters specify the memory range that will be exposed by the typed array view. If both are omitted, all of buffer is viewed; if only length is omitted, the remainder of buffer is viewed.

Examples

Different ways to create a BigUint64Array

// 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]

Specifications

Browser compatibility

See also

• JavaScript typed arrays
• BigInt64Array
• DataView