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30-seconds-of-code/snippets/validateNumber.md
Angelos Chalaris 0425ebefe7 Archive, multitagging, cleanup
Cleaned up the current snippets for consistency and minor problems, added multiple tags to most of them, archived a few.
2018-01-05 16:33:54 +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
```