Constructor Name

Determine the name of a value's constructor.

Usage

var constructorName = require( '@stdlib/utils/constructor-name' );

constructorName( value )

Returns the name of a value's constructor.

var name = constructorName( 'a' );
// returns 'String'

name = constructorName( 5 );
// returns 'Number'

function Beep(){}
name = constructorName( new Beep() );
// returns 'Beep'

description	value	constructor	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(){})()	''

Notes

• If a value's constructor is an anonymous function, the implementation returns an empty string.

  var Beep = function(){};
  
  var name = constructorName( new Beep() );
  // returns ''  

Examples

var constructorName = require( '@stdlib/utils/constructor-name' );

console.log( constructorName( 'a' ) );
// returns 'String'

console.log( constructorName( 5 ) );
// returns 'Number'

console.log( constructorName( NaN ) );
// returns 'Number'

console.log( constructorName( null ) );
// returns 'Null'

console.log( constructorName( undefined ) );
// returns 'Undefined'

console.log( constructorName( true ) );
// returns 'Boolean'

console.log( constructorName( false ) );
// returns 'Boolean'

console.log( constructorName( {} ) );
// returns 'Object'

console.log( constructorName( [] ) );
// returns 'Array'

console.log( constructorName( function noop(){} ) );
// returns 'Function'

console.log( constructorName( /./ ) );
// returns 'RegExp'

console.log( constructorName( new Date() ) );
// returns 'Date'

console.log( constructorName( new Map() ) );
// returns 'Map'

console.log( constructorName( new WeakMap() ) );
// returns 'WeakMap'

console.log( constructorName( new Set() ) );
// returns 'Set'

console.log( constructorName( new WeakSet() ) );
// returns 'WeakSet'

console.log( constructorName( Symbol() ) );
// returns 'Symbol'

console.log( constructorName( new Error() ) );
// returns 'Error'

console.log( constructorName( new TypeError() ) );
// returns 'TypeError'

console.log( constructorName( new SyntaxError() ) );
// returns 'SyntaxError'

console.log( constructorName( new URIError() ) );
// returns 'URIError'

console.log( constructorName( new RangeError() ) );
// returns 'RangeError'

console.log( constructorName( new ReferenceError() ) );
// returns 'ReferenceError'

console.log( constructorName( new EvalError() ) );
// returns 'EvalError'

console.log( constructorName( new Int8Array() ) );
// returns 'Int8Array'

console.log( constructorName( new Uint8Array() ) );
// returns 'Uint8Array'

console.log( constructorName( new Uint8ClampedArray() ) );
// returns 'Uint8ClampedArray'

console.log( constructorName( new Int16Array() ) );
// returns 'Int16Array'

console.log( constructorName( new Uint16Array() ) );
// returns 'Uint16Array'

console.log( constructorName( new Int32Array() ) );
// returns 'Int32Array'

console.log( constructorName( new Uint32Array() ) );
// returns 'Uint32Array'

console.log( constructorName( new Float32Array() ) );
// returns 'Float32Array'

console.log( constructorName( new Float64Array() ) );
// returns 'Float64Array'

console.log( constructorName( new ArrayBuffer() ) );
// returns 'ArrayBuffer'

console.log( constructorName( new Buffer( 'beep' ) ) );
// returns 'Buffer'

console.log( constructorName( Math ) );
// returns 'Math'

console.log( constructorName( JSON ) );
// returns 'JSON'

function Person(){}
console.log( constructorName( new Person() ) );
// returns 'Person'

var Person = function(){};
console.log( constructorName( new Person() ) );
// returns ''