Bitwise AND assignment (&=)
{{jsSidebar("Operators")}}
The bitwise AND assignment (&=) operator performs bitwise AND on the two operands and assigns the result to the left operand.
{{InteractiveExample("JavaScript Demo: Expressions - Bitwise AND assignment", "shorter")}}
let a = 5; // 00000000000000000000000000000101
a &= 3; // 00000000000000000000000000000011
console.log(a); // 00000000000000000000000000000001
// Expected output: 1
Syntax
x &= y
Description
x &= y is equivalent to x = x & y, except that the expression x is only evaluated once.
Examples
Using bitwise AND assignment
let a = 5;
// 5: 00000000000000000000000000000101
// 2: 00000000000000000000000000000010
a &= 2; // 0
let b = 5n;
b &= 2n; // 0n
Specifications
{{Specifications}}
Browser compatibility
{{Compat}}