@stdlib/utils/type-of/README.md

Standard utilities.

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# typeOf

> Determine a value's type.

<section class="usage">

## Usage

```javascript
var typeOf = require( '@stdlib/utils/type-of' );
```

#### typeOf( value )

Returns a value's type.

```javascript
var str = typeOf( 'a' );
// returns 'string'

str = typeOf( 5 );
// returns 'number'
```

| description           | value                               | type                  | notes        |
| --------------------- | ----------------------------------- | --------------------- | ------------ |
| string                | `'beep'`                            | `'string'`            |              |
| number                | `5`                                 | `'number'`            |              |
| NaN                   | `NaN`                               | `'number'`            |              |
| infinity              | `+infinity`/`-infinity`             | `'number'`            |              |
| boolean               | `true`/`false`                      | `'boolean'`           |              |
| null                  | `null`                              | `'null'`              |              |
| undefined             | `undefined`                         | `'undefined'`         |              |
| array                 | `['beep', 5]`                       | `'array'`             |              |
| object                | `{'foo': 'bar'}`                    | `'object'`            |              |
| function              | `function (){}`                     | `'function'`          |              |
| symbol                | `Symbol()`                          | `'symbol'`            | ES2015       |
| regexp                | `/./`                               | `'regexp'`            | Android 4.1+ |
| String                | `new String('beep')`                | `'string'`            |              |
| Number                | `new Number(5)`                     | `'number'`            |              |
| Boolean               | `new Boolean(false)`                | `'boolean'`           |              |
| Object                | `new Object()`                      | `'object'`            |              |
| Array                 | `new Array()`                       | `'array'`             |              |
| Int8Array             | `new Int8Array()`                   | `'int8array'`         |              |
| Uint8Array            | `new Uint8Array()`                  | `'uint8array'`        |              |
| Uint8ClampedArray     | `new Uint8ClampedArray()`           | `'uint8clampedarray'` |              |
| Int16Array            | `new Int16Array()`                  | `'int16array'`        |              |
| Uint16Array           | `new Uint16Array()`                 | `'uint16array'`       |              |
| Int32Array            | `new Int32Array()`                  | `'int32array'`        |              |
| Uint32Array           | `new Uint32Array()`                 | `'uint32array'`       |              |
| Float32Array          | `new Float32Array()`                | `'float32array'`      |              |
| Float64Array          | `new Float64Array()`                | `'float64array'`      |              |
| ArrayBuffer           | `new ArrayBuffer()`                 | `'arraybuffer'`       |              |
| Buffer                | `new Buffer()`                      | `'buffer'`            | Node.js      |
| Date                  | `new Date()`                        | `'date'`              |              |
| RegExp                | `new RegExp('.')`                   | `'regexp'`            | Android 4.1+ |
| Function              | `new Function('x', 'return x')`     | `'function'`          |              |
| Map                   | `new Map()`                         | `'map'`               | ES2015       |
| WeakMap               | `new WeakMap()`                     | `'weakmap'`           | ES2015       |
| Set                   | `new Set()`                         | `'set'`               | ES2015       |
| WeakSet               | `new WeakSet()`                     | `'weakset'`           | ES2015       |
| Error                 | `new Error()`                       | `'error'`             |              |
| TypeError             | `new TypeError()`                   | `'typeerror'`         |              |
| SyntaxError           | `new SyntaxError()`                 | `'syntaxerror'`       |              |
| ReferenceError        | `new ReferenceError()`              | `'referenceerror'`    |              |
| URIError              | `new URIError()`                    | `'urierror'`          |              |
| RangeError            | `new RangeError()`                  | `'rangeerror'`        |              |
| EvalError             | `new EvalError()`                   | `'evalerror'`         |              |
| Math                  | `Math`                              | `'math'`              |              |
| JSON                  | `JSON`                              | `'json'`              | IE8+         |
| arguments             | `(function(){return arguments;})()` | `'arguments'`         | IE9+         |
| custom constructor    | `new Beep()`                        | `'beep'`              |              |
| anonymous constructor | `new (function(){})()`              | `''`                  |              |

</section>

<!-- /.usage -->

<section class="examples">

## Examples

<!-- eslint-disable no-restricted-syntax, no-empty-function, func-names, func-style -->

<!-- eslint no-undef: "error" -->

```javascript
var Float32Array = require( '@stdlib/array/float32' );
var Float64Array = require( '@stdlib/array/float64' );
var Int8Array = require( '@stdlib/array/int8' );
var Int16Array = require( '@stdlib/array/int16' );
var Int32Array = require( '@stdlib/array/int32' );
var Uint8Array = require( '@stdlib/array/uint8' );
var Uint8ClampedArray = require( '@stdlib/array/uint8c' );
var Uint16Array = require( '@stdlib/array/uint16' );
var Uint32Array = require( '@stdlib/array/uint32' );
var ArrayBuffer = require( '@stdlib/array/buffer' );
var Symbol = require( '@stdlib/symbol/ctor' );
var typeOf = require( '@stdlib/utils/type-of' );

var str = typeOf( 'a' );
// returns 'string'

str = typeOf( 5 );
// returns 'number'

str = typeOf( NaN );
// returns 'number'

str = typeOf( Infinity );
// returns 'number'

str = typeOf( true );
// returns 'boolean'

str = typeOf( false );
// returns 'boolean'

str = typeOf( void 0 );
// returns 'undefined'

str = typeOf( null );
// returns 'null'

str = typeOf( [] );
// returns 'array'

str = typeOf( {} );
// returns 'object'

str = typeOf( function noop() {} );
// returns 'function'

str = typeOf( new Map() );
// returns 'map'

str = typeOf( new WeakMap() );
// returns 'weakmap'

str = typeOf( new Set() );
// returns 'set'

str = typeOf( new WeakSet() );
// returns 'weakset'

str = typeOf( Symbol( 'beep' ) );
// returns 'symbol'

str = typeOf( new Error( 'beep' ) );
// returns 'error'

str = typeOf( new TypeError( 'beep' ) );
// returns 'typeerror'

str = typeOf( new SyntaxError( 'beep' ) );
// returns 'syntaxerror'

str = typeOf( new ReferenceError( 'beep' ) );
// returns 'referenceerror'

str = typeOf( new URIError( 'beep' ) );
// returns 'urierror'

str = typeOf( new EvalError( 'beep' ) );
// returns 'evalerror'

str = typeOf( new RangeError( 'beep' ) );
// returns 'rangeerror'

str = typeOf( new Date() );
// returns 'date'

str = typeOf( /./ );
// returns 'regexp'

str = typeOf( Math );
// returns 'math'

str = typeOf( JSON );
// returns 'json'

str = typeOf( new Int8Array( 10 ) );
// returns 'int8array'

str = typeOf( new Uint8Array( 10 ) );
// returns 'uint8array'

str = typeOf( new Int16Array( 10 ) );
// returns 'int16array'

str = typeOf( new Uint16Array( 10 ) );
// returns 'uint16array'

str = typeOf( new Int32Array( 10 ) );
// returns 'int32array'

str = typeOf( new Uint32Array( 10 ) );
// returns 'uint32array'

str = typeOf( new Float32Array( 10 ) );
// returns 'float32array'

str = typeOf( new Float64Array( 10 ) );
// returns 'float64array'

str = typeOf( new ArrayBuffer( 10 ) );
// returns 'arraybuffer'

function Person1() {
    return this;
}
str = typeOf( new Person1() );
// returns 'person1'

var Person2 = function () {
    return this;
};
str = typeOf( new Person2() );
// returns ''
```

</section>

<!-- /.examples -->

<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->

<section class="related">

* * *

## See Also

-   <span class="package-name">[`@stdlib/utils/constructor-name`][@stdlib/utils/constructor-name]</span><span class="delimiter">: </span><span class="description">determine the name of a value's constructor.</span>
-   <span class="package-name">[`@stdlib/utils/native-class`][@stdlib/utils/native-class]</span><span class="delimiter">: </span><span class="description">determine the specification defined classification of an object.</span>

</section>

<!-- /.related -->

<!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="links">

<!-- <related-links> -->

[@stdlib/utils/constructor-name]: https://github.com/stdlib-js/utils/tree/main/constructor-name

[@stdlib/utils/native-class]: https://github.com/stdlib-js/utils/tree/main/native-class

<!-- </related-links> -->

</section>

<!-- /.links -->