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Multiplication 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 *= operator performs multiplication on the two operands and assigns the result to the left operand.

Try it

let a = 2;

console.log((a *= 3));
// Expected output: 6

console.log((a *= "hello"));
// Expected output: NaN

Syntax

x *= y

Description

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

Examples

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Multiplication assignment using numbers

let bar = 5;
bar *= 2; // 10

Other non-BigInt values are coerced to numbers:

let bar = 5;
bar *= "foo"; // NaN

Multiplication assignment using BigInts

let foo = 3n;
foo *= 2n; // 6n
foo *= 1; // TypeError: Cannot mix BigInt and other types, use explicit conversions

Specifications

Browser compatibility

Desktop Mobile Server
Chrome Edge Firefox Opera Safari Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet WebView Android WebView on iOS Bun Deno Node.js
Multiplication_assignment 1 12 1 3 1 18 4 10.1 1 1.0 4.4 1 1.0.0 1.0 0.10.0

See also

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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Multiplication_assignment