Bitwise OR assignment (|=)

The bitwise OR assignment (|=) operator performs bitwise OR on the two operands and assigns the result to the left operand.

{{InteractiveExample("JavaScript Demo: Bitwise OR assignment (|=) operator", "shorter")}}

```js interactive-example let a = 5; // 00000000000000000000000000000101 a |= 3; // 00000000000000000000000000000011

console.log(a); // 00000000000000000000000000000111 // Expected output: 7

## Syntax

```js-nolint
x |= y

Description#

x |= y is equivalent to x = x | y, except that the expression x is only evaluated once.

Examples#

Using bitwise OR assignment#

let a = 5;
a |= 2; // 7
// 5: 00000000000000000000000000000101
// 2: 00000000000000000000000000000010
// -----------------------------------
// 7: 00000000000000000000000000000111

let b = 5n;
b |= 2n; // 7n

Specifications#

{{Specifications}}

Browser compatibility#

{{Compat}}

See also#

• Assignment operators in the JS guide
• Bitwise OR (|)
• Logical OR assignment (||=)