Number.isNaN
isNaN – Evaluates an argument to determine if it is not a number.
Description
Number.isNaN(mixed variable)
Parameters
| Name |
Description |
Type |
Default |
Optional |
| variable |
|
mixed |
|
No |
Return values
Returns true if the value is not a number, otherwise false.
Changelog
| Version |
Description |
| ES 6 |
Introduced. |
Examples
Example #1 – isNaN example
console.log(Number.isNaN(NaN)); // true
console.log(Number.isNaN("string")); // false
console.log(Number.isNaN("12")); // false
console.log(Number.isNaN(12)); // false
console.log(Number.isNaN(12.42)); // false
console.log(Number.isNaN("")); // false
console.log(Number.isNaN("\n\t")); // false
console.log(Number.isNaN(null)); // false
console.log(Number.isNaN(true)); // false
console.log(Number.isNaN(undefined)); // false
console.log(Number.isNaN(Infinity)); // false
External references