Exponentiation assignment (**=)

The exponentiation assignment (**=) operator performs exponentiation on the two operands and assigns the result to the left operand.

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Syntax

js
x **= y

Description

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

Examples

Exponentiation assignment using numbers

js
let bar = 5;
bar **= 2; // 25

Other non-BigInt values are coerced to numbers:

js
let baz = 5;
baz **= "foo"; // NaN

Exponentiation assignment using BigInts

js
let foo = 3n;
foo **= 2n; // 9n
foo **= 1; // TypeError: Cannot mix BigInt and other types, use explicit conversions

Specifications

Specification
ECMAScript Language Specification
# sec-assignment-operators

Browser compatibility

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Firefox
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Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
Deno
Node.js
Exponentiation assignment (x **= y)

See also