Bitwise OR assignment (|=)
BaselineWidely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
Thebitwise OR assignment (|=) operator performsbitwise OR on the two operands and assigns the result to the left operand.
Try it
let a = 5; // 00000000000000000000000000000101a |= 3; // 00000000000000000000000000000011console.log(a); // 00000000000000000000000000000111// Expected output: 7Syntax
js
x |= yDescription
x |= y is equivalent tox = x | y, except that the expressionx is only evaluated once.
Examples
Using bitwise OR assignment
js
let a = 5;a |= 2; // 7// 5: 00000000000000000000000000000101// 2: 00000000000000000000000000000010// -----------------------------------// 7: 00000000000000000000000000000111let b = 5n;b |= 2n; // 7nSpecifications
| Specification |
|---|
| ECMAScript® 2026 Language Specification # sec-assignment-operators |