Sets the result of a bitwise AND operation on the value of a variable and the value of an expression. The variable and the expression are treated as 32-bit integers.
result &= expression
Using this operator is the same as specifying:
result = result & expression
The Bitwise AND Operator (&) looks at the binary representation of the values of
expression and does a bitwise AND operation on them. The output of this operation behaves like this:
// 9 is 00000000000000000000000000001001 var expr1 = 9; // 5 is 00000000000000000000000000000101 var expr2 = 5; // 1 is 00000000000000000000000000000001 expr1 &= expr2; document.write(expr1);
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, Internet Explorer 10 standards, Internet Explorer 11 standards. Also supported in Store apps (Windows 8 and Windows Phone 8.1). See Version Information.