Bitwise AND Operator (&) (JavaScript)

Performs a bitwise AND on two expressions.

result = expression1 & expression2


Any variable.


Any expression.


Any expression.

The & operator looks at the binary representation of the values of two expressions and does a bitwise AND operation on them. The result of this operation behaves as follows:

0101   (expression1)
1100   (expression2)
0100   (result)

Any time both of the expressions have a 1 in a digit, the result has a 1 in that digit. Otherwise, the result has a 0 in that digit.

Supported in the following document modes: Quirks, Internet Explorer 6 standards, Internet Explorer 7 standards, Internet Explorer 8 standards, Internet Explorer 9 standards. See Version Information.