Atomics.store()

The Atomics.store() static method stores a given value at a given position in the array and returns that value. This atomic operation guarantees that the write is tear-free, and that all atomic writes are sequentially consistent.

Note that unlike many other Atomic methods, store() returns the new value instead of the old value. To get the old value, use Atomics.exchange() instead.

Syntax

js
Atomics.store(typedArray, index, value)

Parameters

typedArray

An integer typed array. One of Int8Array, Uint8Array, Int16Array, Uint16Array, Int32Array, Uint32Array, BigInt64Array, or BigUint64Array.

index

The position in the typedArray to store a value in.

value

The number to store.

Return value

The value that has been stored.

Exceptions

TypeError

Thrown if typedArray is not one of the allowed integer types.

RangeError

Thrown if index is out of bounds in the typedArray.

Examples

Note that these examples cannot be run directly from the console or an arbitrary web page, because SharedArrayBuffer is not defined unless its security requirements are met.

Using Atomics.store()

js
// Create a SharedArrayBuffer with a size in bytes
const sab = new SharedArrayBuffer(1024);
const ta = new Uint8Array(sab);

console.log(Atomics.store(ta, 0, 12)); // 12, the new/current value
console.log(Atomics.load(ta, 0)); // 12, the new/current value

Specifications

See also