IsNaN () differs from number.isnan ()

1. IsNaN () is the ES5 method and number.isnan () is the ES6 method.

2. IsNaN is literally “NaN or not”, but is not meant to be. IsNaN is meant to convert an argument to a Number using the Number method. If the conversion succeeds, isNaN returns false, and if it fails, isNaN returns true. You can’t use this method if you want to determine whether a value is strictly NaN.

3. ES6 provides the number.isnan () method to determine whether a value is strictly equal to NaN. It first checks if the value passed is numeric and returns false if it is not.

The difference between:

• The isNaN method converts the type first, while the number. isNaN method does not;

• IsNaN cannot be used to determine whether it is strictly equal to NaN. The number. isNaN method is available