The Boolean() type cast returns true when
the value is a string with at least one character,
a number other than 0, or
an object;
The Boolean() type cast returns false when
the value is an empty string,
the number 0,
undefined, or
null.
var b1 = Boolean(""); //false -- empty string
var b2 = Boolean("JavaScript"); //true -- non-empty string
var b3 = Boolean(100); //true -- non-zero number
var b4 = Boolean(null); //false -- null
var b5 = Boolean(0); //false -- zero
var b6 = Boolean(new Object()); //true -- object