Question

What is the difference between isNaN and Number.isNaN?

Answer 1

1. isNaN: The global function isNaN converts the argument to a Number and returns true if the resulting value is NaN.
2. Number.isNaN: This method does not convert the argument. But it returns true when the type is a Number and value is NaN.

Let's see the difference with an example,

isNaN(‘hello’);   // true
Number.isNaN('hello'); // false