NaN property represents “Not-a-Number” value. It indicates a value which is not a legal number.
typeof of a NaN will return a Number .
To check if a value is NaN, we use the isNaN() function,
Note : isNaN() function converts the given value to a Number type, and then equates to NaN.
isNaN("Hello") // Returns true
isNaN(345) // Returns false
isNaN('1') // Returns false, since '1' is converted to Number type which results in 0 ( a number)
isNaN(true) // Returns false, since true converted to Number type results in 1 ( a number)
isNaN(false) // Returns false
isNaN(undefined) // Returns true
