is-nan-x

ES6-compliant shim for Number.isNaN - the global isNaN returns false positives.

module.exports(value) ⇒ boolean ⏏

This method determines whether the passed value is NaN and its type is Number. It is a more robust version of the original, global isNaN().

Kind: Exported function
Returns: boolean - true if the given value is NaN and its type is Number; otherwise, false.

| Param | Type | Description | | ----- | --------------- | ------------------------------- | | value | * | The value to be tested for NaN. |

Example

import numberIsNaN from 'is-nan-x';

console.log(numberIsNaN(NaN)); // true
console.log(numberIsNaN(Number.NaN)); // true
console.log(numberIsNaN(0 / 0)); // true

// e.g. these would have been true with global isNaN()
console.log(numberIsNaN('NaN')); // false
console.log(numberIsNaN(undefined)); // false
console.log(numberIsNaN({}); // false
console.log(numberIsNaN('blabla')); // false

// These all return false
console.log(numberIsNaN(true));
console.log(numberIsNaN(null));
console.log(numberIsNaN(37));
console.log(numberIsNaN('37'));
console.log(numberIsNaN('37.37'));
console.log(numberIsNaN(''));
console.log(numberIsNaN(' '));