Web/JavaScript/Reference/Operators/Bitwise OR assignment

The bitwise OR assignment operator (|=) uses the binary representation of both operands, does a bitwise OR operation on them and assigns the result to the variable.

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Syntax

Operator: x |= y
Meaning:  x = x | y

Examples

Using bitwise OR assignment

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

Specifications

Specification
ECMAScript (ECMA-262)The definition of 'Assignment operators' in that specification.

Browser compatibility

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.

Update compatibility data on GitHub

	Desktop						Mobile						Server
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet	Node.js
= y)	Chrome Full support 1	Edge Full support 12	Firefox Full support 1	IE Full support 3	Opera Full support 3	Safari Full support 1	WebView Android Full support 1	Chrome Android Full support 18	Firefox Android Full support 4	Opera Android Full support 10.1	Safari iOS Full support 1	Samsung Internet Android Full support 1.0	nodejs Full support 0.1.100

Legend

Full support  

Full support

See also

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

Bitwise OR assignment (|=) by Mozilla Contributors is licensed under CC-BY-SA 2.5.