Learn ECMAScript - Second Edition

Using the Atomics.add(typedArray, index, value) method

Atomics.add is a way to add a particular value to a particular index in a typed array. It is fairly simple to understand and write:

const sab = new SharedArrayBuffer(1);const arr = new Uint8Array(sab);arr[0] = 5;console.log(Atomics.add(arr, 0, 10));console.log(Atomics.load(arr, 0));

Atomics.add is, again, a thread-safe way of performing arr[0] += 10.

This outputs:

515

 Atomics.add returns the old value at that index. The value is updated at that index after the command is run.