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 v = constructorName( 'a' );
// returns 'String'

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

function Beep() {
    return this;
}
v = 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 () {
    return this;
};

var v = constructorName( new Beep() );
// returns ''

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 Buffer = require( '@stdlib/buffer/ctor' );
var Symbol = require( '@stdlib/symbol/ctor' );
var constructorName = require( '@stdlib/utils/constructor-name' );

function noop() {
    // Do nothing...
}

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

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

v = constructorName( NaN );
// returns 'Number'

v = constructorName( null );
// returns 'Null'

v = constructorName( void 0 );
// returns 'Undefined'

v = constructorName( true );
// returns 'Boolean'

v = constructorName( false );
// returns 'Boolean'

v = constructorName( {} );
// returns 'Object'

v = constructorName( [] );
// returns 'Array'

v = constructorName( noop );
// returns 'Function'

v = constructorName( /./ );
// returns 'RegExp'

v = constructorName( new Date() );
// returns 'Date'

v = constructorName( new Map() );
// returns 'Map'

v = constructorName( new WeakMap() );
// returns 'WeakMap'

v = constructorName( new Set() );
// returns 'Set'

v = constructorName( new WeakSet() );
// returns 'WeakSet'

v = constructorName( Symbol( 'beep' ) );
// returns 'Symbol'

v = constructorName( new Error() );
// returns 'Error'

v = constructorName( new TypeError() );
// returns 'TypeError'

v = constructorName( new SyntaxError() );
// returns 'SyntaxError'

v = constructorName( new URIError() );
// returns 'URIError'

v = constructorName( new RangeError() );
// returns 'RangeError'

v = constructorName( new ReferenceError() );
// returns 'ReferenceError'

v = constructorName( new EvalError() );
// returns 'EvalError'

v = constructorName( new Int8Array() );
// returns 'Int8Array'

v = constructorName( new Uint8Array() );
// returns 'Uint8Array'

v = constructorName( new Uint8ClampedArray() );
// returns 'Uint8ClampedArray'

v = constructorName( new Int16Array() );
// returns 'Int16Array'

v = constructorName( new Uint16Array() );
// returns 'Uint16Array'

v = constructorName( new Int32Array() );
// returns 'Int32Array'

v = constructorName( new Uint32Array() );
// returns 'Uint32Array'

v = constructorName( new Float32Array() );
// returns 'Float32Array'

v = constructorName( new Float64Array() );
// returns 'Float64Array'

v = constructorName( new ArrayBuffer() );
// returns 'ArrayBuffer'

v = constructorName( new Buffer( 'beep' ) );
// returns 'Buffer'

v = constructorName( Math );
// returns 'Math'

v = constructorName( JSON );
// returns 'JSON'

function Person1() {
    return this;
}
v = constructorName( new Person1() );
// returns 'Person1'

var Person2 = function () {
    return this;
};
v = constructorName( new Person2() );
// returns ''