The new.target pseudo-property lets you detect whether a function or constructor was called using the new operator. In constructors and functions invoked using the new operator, new.target returns a reference to the constructor or function. In normal function calls, new.target is undefined .

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Syntax

new.target

Description

The new.target syntax consists of the keyword new , a dot, and the identifier target . Normally, the left-hand side of the dot is the object on which property access is performed, but here, new is not an object.

The new.target pseudo-property is available in all functions.

In class constructors, it refers to the constructed class.

In ordinary functions, it refers to the function itself, assuming it was invoked via the new operator; otherwise new.target is undefined .

In arrow functions, new.target is inherited from the surrounding scope.

Examples

new.target in function calls

In normal function calls (as opposed to constructor function calls), new.target is undefined . This lets you detect whether a function was called with new as a constructor.

function Foo() { if (!new.target) { throw 'Foo() must be called with new' } console.log('Foo instantiated with new') } new Foo() // logs "Foo instantiated with new" Foo() // throws "Foo() must be called with new"

new.target in constructors

In class constructors, new.target refers to the constructor that was directly invoked by new . This is also the case if the constructor is in a parent class and was delegated from a child constructor.

class A { constructor() { console.log(new.target.name) } } class B extends A { constructor() { super() } } let a = new A() // logs "A" let b = new B() // logs "B" class C { constructor() { console.log(new.target) } } class D extends C { constructor() { super() } } let c = new C() // logs class C{constructor(){console.log(new.target);}} let d = new D() // logs class D extends C{constructor(){super();}}

Thus from the above example of class C and D , it seems that new.target points to the class definition of class which is initialized. For example, when d was initialized using new D() , the class definition of D was printed; and similarly, in case of c , the class C was printed.

Specifications

Browser compatibility

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.

Update compatibility data on GitHub Desktop Mobile Server Chrome Edge Firefox Internet Explorer Opera Safari Android webview Chrome for Android Firefox for Android Opera for Android Safari on iOS Samsung Internet Node.js new.target Chrome Full support 46 Edge Full support 13 Firefox Full support 41 IE No support No Opera Full support 33 Safari Full support 11 WebView Android Full support 46 Chrome Android Full support 46 Firefox Android Full support 41 Opera Android Full support 33 Safari iOS Full support 11 Samsung Internet Android Full support 5.0 nodejs Full support 5.0.0 Legend Full support Full support No support No support

See also