Bitwise AND assignment (&=)
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
The bitwise AND assignment (&=
) operator performs bitwise AND on the two operands and assigns the result to the left operand.
Try it
let a = 5; // 00000000000000000000000000000101
a &= 3; // 00000000000000000000000000000011
console.log(a); // 00000000000000000000000000000001
// Expected output: 1
Syntax
js
x &= y
Description
x &= y
is equivalent to x = x & y
, except that the expression x
is only evaluated once.
Examples
Using bitwise AND assignment
js
let a = 5;
// 5: 00000000000000000000000000000101
// 2: 00000000000000000000000000000010
a &= 2; // 0
let b = 5n;
b &= 2n; // 0n
Specifications
Specification |
---|
ECMAScript® 2025 Language Specification # sec-assignment-operators |
Browser compatibility
Report problems with this compatibility data on GitHubdesktop | mobile | server | ||||||||||||
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Bitwise AND assignment ( x &= y ) |
Legend
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- Full support
- Full support
The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.