JavaScript Internals (521 Qs)•Part 2: Promises, Callbacks, Async & Strict Mode (54 - 103)
What is NaN property
The NaN property is a global property that represents "Not-a-Number" value. i.e, It indicates that a value is not a legal number. It is very rare to use NaN in a program but it can be used as return value for few cases
javascript
Math.sqrt(-1);
parseInt("Hello");