JavaScript Logic Operators with Booleans


Example

var x = true,
    y = false;

AND

This operator will return true if both of the expressions evaluate to true. This boolean operator will employ short-circuiting and will not evaluate y if x evaluates to false.

x && y;

This will return false, because y is false.

OR

This operator will return true if one of the two expressions evaluate to true. This boolean operator will employ short-circuiting and y will not be evaluated if x evaluates to true.

x || y;

This will return true, because x is true.

NOT

This operator will return false if the expression on the right evaluates to true, and return true if the expression on the right evaluates to false.

!x;

This will return false, because x is true.