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'
descriptionvaluetypenotes
string'beep''string'
number5'number'
NaNNaN'number'
infinity+infinity/-infinity'number'
booleantrue/false'boolean'
nullnull'null'
undefinedundefined'undefined'
array['beep', 5]'array'
object{'foo': 'bar'}'object'
functionfunction (){}'function'
symbolSymbol()'symbol'ES2015
regexp/./'regexp'Android 4.1+
Stringnew String('beep')'string'
Numbernew Number(5)'number'
Booleannew Boolean(false)'boolean'
Objectnew Object()'object'
Arraynew Array()'array'
Int8Arraynew Int8Array()'int8array'
Uint8Arraynew Uint8Array()'uint8array'
Uint8ClampedArraynew Uint8ClampedArray()'uint8clampedarray'
Int16Arraynew Int16Array()'int16array'
Uint16Arraynew Uint16Array()'uint16array'
Int32Arraynew Int32Array()'int32array'
Uint32Arraynew Uint32Array()'uint32array'
Float32Arraynew Float32Array()'float32array'
Float64Arraynew Float64Array()'float64array'
ArrayBuffernew ArrayBuffer()'arraybuffer'
Buffernew Buffer()'buffer'Node.js
Datenew Date()'date'
RegExpnew RegExp('.')'regexp'Android 4.1+
Functionnew Function('x', 'return x')'function'
Mapnew Map()'map'ES2015
WeakMapnew WeakMap()'weakmap'ES2015
Setnew Set()'set'ES2015
WeakSetnew WeakSet()'weakset'ES2015
Errornew Error()'error'
TypeErrornew TypeError()'typeerror'
SyntaxErrornew SyntaxError()'syntaxerror'
ReferenceErrornew ReferenceError()'referenceerror'
URIErrornew URIError()'urierror'
RangeErrornew RangeError()'rangeerror'
EvalErrornew EvalError()'evalerror'
MathMath'math'
JSONJSON'json'IE8+
arguments(function(){return arguments;})()'arguments'IE9+
custom constructornew Beep()'beep'
anonymous constructornew (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 ''
Did you find this page helpful?