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

Specification
ECMAScript Language Specification (ECMAScript) # sec-atomics.sub

Browser compatibility

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	WebView Android	Chrome Android	Firefox for Android	Opera Android	Safari on IOS	Samsung Internet
`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 Support was removed to mitigate speculative execution side-channel attacks (Windows blog).	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.