What is NaN?

Answer 1

A pseudo value standing for Not A Number: occurs when a calcul isn't numerically valid ( don't produce a number ), to store an explicit value differet from 'none' and 'undefined'...

Answer 2

The NaN property represents "Not-a-Number" value. This property indicates that a value is not a legal number.
Use the isNaN() global function to check if a value is a NaN value.

Answer 3

NotANumber 0/0 , √-1

Answer 4

thanks