Logical AND Operator (&&) (JavaScript)

Performs a logical conjunction on two expressions.


result = expression1 && expression2   


Any variable.

Any expression.

Any expression.


If expression1 evaluates to false, result is expression1. Otherwise, result is expression2. Consequently, the operation returns true if both operands are true; otherwise, it returns false.

JavaScript uses the following rules for converting non-Boolean values to Boolean values:

  • All objects are considered to be true.

  • Strings are considered to be false if they are empty.

  • null and undefined are considered to be false.

  • A Number is false if it is zero.


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.

See Also

Operator Precedence
Operator Summary (JavaScript)