Multiplication assignment (*=) - JavaScript | MDN

Try it

let a = 2;

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

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

Syntax

Description

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

Examples

Multiplication assignment using numbers

js

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

Other non-BigInt values are coerced to numbers:

js

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

Multiplication assignment using BigInts

js

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

Specifications

Specification
ECMAScript® 2027 Language Specification
# sec-assignment-operators

Browser compatibility

See also

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