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.

Atomics.sub(typedArray, index, value)

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.

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

• 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.

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

• Atomics
• Atomics.add()