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30-seconds-of-code/snippets/validateNumber.md
Angelos Chalaris 97c250bcfb Updated examples
2017-12-27 16:35:25 +02:00

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### validateNumber
Returns `true` if the given value is a number, `false` otherwise.
Use `!isNaN` in combination with `parseFloat()` to check if the argument is a number.
Use `isFinite()` to check if the number is finite.
Use `Number()` to check if the coercion holds.
```js
const validateNumber = n => !isNaN(parseFloat(n)) && isFinite(n) && Number(n) == n;
```
```js
validateNumber('10') // true
```