javaScript uses a fixed number of bits, namely 64 of them, to store a single number value.
compare
when null or undefined occurs on either side of the Operator, it PRoduces true only if both sides are one of null or undefined..When you want to test whether a value has a real value instead of null or undefined, you can simply compare it to null with the == (or !=) operator.The isNaN function is a standard Javascript function that returns true only if the argument it is given is NaN.
