Performs a logical conjunction on two expressions.
If both expressions evaluate to true, result is true. If either expression evaluates to false, result is false.
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. Also supported in Windows Store apps. See Version Information.