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Atomics.sub()

The static Atomics.sub() method substracts a given value at a given position in the array and returns the old value at that position. This atomic operation guarantees that no other write happens until the modified value is written back.

Syntax

Atomics.sub(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 subtract a value from.

value

The number to subtract.

Return value

The old value at the given position (typedArray[index]).

Exceptions

  • Throws a TypeError, if typedArray is not one of the allowed integer types.
  • Throws a RangeError, if index is out of bounds in the typedArray.

Examples

Using sub

const sab = new SharedArrayBuffer(1024);
const ta = new Uint8Array(sab);
ta[0] = 48;

Atomics.sub(ta, 0, 12); // returns 48, the old value
Atomics.load(ta, 0); // 36

Specifications

Browser compatibility

Desktop Mobile Server
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet Deno Node.js
sub
68
60-63
Chrome disabled SharedArrayBuffer on January 5, 2018 to help reduce the efficacy of speculative side-channel attacks. This was a temporary removal while mitigations were put in place.
79
16-17
78
57
Support was disabled by default to mitigate speculative execution side-channel attacks (Mozilla Security Blog).
55-57
46-55
No
No
10.1-11.1
60-63
Chrome disabled SharedArrayBuffer on January 5, 2018 to help reduce the efficacy of speculative side-channel attacks. This is intended as a temporary measure until other mitigations are in place.
60-63
Chrome disabled SharedArrayBuffer on January 5, 2018 to help reduce the efficacy of speculative side-channel attacks. This is intended as a temporary measure until other mitigations are in place.
57
Support was disabled by default to mitigate speculative execution side-channel attacks (Mozilla Security Blog).
55-57
46-55
No
10.3-11.3
No
Chrome disabled SharedArrayBuffer on January 5, 2018 to help reduce the efficacy of speculative side-channel attacks. This is intended as a temporary measure until other mitigations are in place.
1.0
8.10.0

See also

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https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Atomics/sub