# isUint8Array

Evaluates whether the given value is of type [UInt8Array](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Uint8Array)

```javascript
import isUint8Array from 'deep-waters/isUint8Array';

const x = new Uint8Array([21, 31]);

isUint8Array(x); // → true

isUint8Array(20); // → false
isUint8Array("hello"); // → false
isUint8Array(undefined"); // → false
```

isUint8Array, like any other type validator, is mostly used in [composed](broken://pages/-M6Ac8HwrWJzjYtU2tLT) validators:

```javascript
import isString from 'deep-waters/isString';
import matchesPattern from 'deep-waters/matchesPattern';

const isEmail = compose(
  isString,
  matchesPattern(/^\w+([.-]?\w+)*@\w+([.-]?\w+)*(\.\w{2,3})+$/),
);
```

{% hint style="success" %}
isUint8Array is built on top of the [ofClass](/deep-waters/validators/ofclass.md) validator and rely on `Object.prototype.toString` to check on the received value type in order to avoid [typeof weird behaviours ](https://stackoverflow.com/questions/18808226/why-is-typeof-null-object)and encouraging a **runtime strict type validation**.
{% endhint %}


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