typeOf

Determine a value's type.

Usage

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

typeOf( value )

Returns a value's type.

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(){})()`	`''`

Examples

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 ''