Atomics.and() - JavaScript | MDN
Syntax
js
Atomics.and(typedArray, index, value)
Parameters
typedArray-
An integer typed array. One of
Int8Array,Uint8Array,Int16Array,Uint16Array,Int32Array,Uint32Array,BigInt64Array, orBigUint64Array. index-
The position in the
typedArrayto compute the bitwise AND. value-
The number to compute the bitwise AND with.
Return value
The old value at the given position (typedArray[index]).
Exceptions
TypeError-
Thrown if
typedArrayis not one of the allowed integer types. RangeError-
Thrown if
indexis out of bounds in thetypedArray.
Description
The bitwise AND operation only yields 1, if both a and b are 1. The truth table for the AND operation is:
a |
b |
a & b |
|---|---|---|
| 0 | 0 | 0 |
| 0 | 1 | 0 |
| 1 | 0 | 0 |
| 1 | 1 | 1 |
For example, a bitwise AND of 5 & 1 results in 0001 which is 1 in decimal.
5 0101 1 0001 ---- 1 0001
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.and()
js
// Create a SharedArrayBuffer with a size in bytes
const sab = new SharedArrayBuffer(1024);
// Create a view and set the value of the 0 index
const ta = new Uint8Array(sab);
ta[0] = 7;
// 7 (0111) AND 10 (1010) = 2 (0010)
console.log(Atomics.and(ta, 0, 10)); // 7, the old value
console.log(Atomics.load(ta, 0)); // 2, the new/current value
Specifications
| Specification |
|---|
| ECMAScript® 2026 Language Specification # sec-atomics.and |