Determine the name of a value's constructor.
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> Determine the name of a value's constructor.
``bash`
npm install @stdlib/utils-constructor-name
`javascript`
var constructorName = require( '@stdlib/utils-constructor-name' );
#### constructorName( value )
Returns the name of a value's constructor.
`javascript
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' | |5
| number | | 'Number' | |NaN
| NaN | | 'Number' | |+infinity
| infinity | /-infinity | 'Number' | |true
| boolean | /false | 'Boolean' | |null
| null | | 'Null' | |undefined
| undefined | | 'Undefined' | |['beep', 5]
| array | | 'Array' | |{'foo': 'bar'}
| object | | 'Object' | |function (){}
| function | | 'Function' | |Symbol()
| symbol | | 'Symbol' | ES2015 |/./
| regexp | | 'RegExp' | Android 4.1+ |new String('beep')
| String | | 'String' | |new Number(5)
| Number | | 'Number' | |new Boolean(false)
| Boolean | | 'Boolean' | |new Object()
| Object | | 'Object' | |new Array()
| Array | | 'Array' | |new Int8Array()
| Int8Array | | 'Int8Array' | |new Uint8Array()
| Uint8Array | | 'Uint8Array' | |new Uint8ClampedArray()
| Uint8ClampedArray | | 'Uint8ClampedArray' | |new Int16Array()
| Int16Array | | 'Int16Array' | |new Uint16Array()
| Uint16Array | | 'Uint16Array' | |new Int32Array()
| Int32Array | | 'Int32Array' | |new Uint32Array()
| Uint32Array | | 'Uint32Array' | |new Float32Array()
| Float32Array | | 'Float32Array' | |new Float64Array()
| Float64Array | | 'Float64Array' | |new ArrayBuffer()
| ArrayBuffer | | 'ArrayBuffer' | |new Buffer()
| Buffer | | 'Buffer' | Node.js |new Date()
| Date | | 'Date' | |new RegExp('.')
| RegExp | | 'RegExp' | Android 4.1+ |new Function('x', 'return x')
| Function | | 'Function' | |new Map()
| Map | | 'Map' | ES2015 |new WeakMap()
| WeakMap | | 'WeakMap' | ES2015 |new Set()
| Set | | 'Set' | ES2015 |new WeakSet()
| WeakSet | | 'WeakSet' | ES2015 |new Error()
| Error | | 'Error' | |new TypeError()
| TypeError | | 'TypeError' | |new SyntaxError()
| SyntaxError | | 'SyntaxError' | |new ReferenceError()
| ReferenceError | | 'ReferenceError' | |new URIError()
| URIError | | 'URIError' | |new RangeError()
| RangeError | | 'RangeError' | |new EvalError()
| EvalError | | 'EvalError' | |Math
| Math | | 'Math' | |JSON
| JSON | | 'JSON' | IE8+ |(function(){return arguments;})()
| arguments | | 'Arguments' | IE9+ |new Beep()
| custom constructor | | 'Beep' | |new (function(){})()
| anonymous constructor | | '' | |
- If a value's constructor is an anonymous function, the implementation returns an empty string.
`javascript
var Beep = function () {
return this;
};
var v = constructorName( new Beep() );
// returns ''
`
`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 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 ''
`
*
- [@stdlib/utils-function-name][@stdlib/utils/function-name]: determine a function's name.
*
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For more information on the project, filing bug reports and feature requests, and guidance on how to develop [stdlib][stdlib], see the main project [repository][stdlib].
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---
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[deno-url]: https://github.com/stdlib-js/utils-constructor-name/tree/deno
[deno-readme]: https://github.com/stdlib-js/utils-constructor-name/blob/deno/README.md
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[umd-readme]: https://github.com/stdlib-js/utils-constructor-name/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/utils-constructor-name/tree/esm
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