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The Array[@@species] accessor property returns the Array constructor.

Syntax

Array[Symbol.species]

Return value

The Array constructor.

Description

The species accessor property returns the default constructor for Array objects. Subclass constructors may override it to change the constructor assignment.

Examples

Species in ordinary objects

The species property returns the default constructor function, which is the Array constructor for Array objects:

Array[Symbol.species]; // function Array()

Species in derived objects

In a derived collection object (e.g. your custom array MyArray), the MyArray species is the MyArray constructor. However, you might want to overwrite this, in order to return parent Array objects in your derived class methods:

class MyArray extends Array {
  // Overwrite MyArray species to the parent Array constructor
  static get [Symbol.species]() { return Array; }
}

Specifications

Browser compatibilityUpdate compatibility data on GitHub

Desktop
Chrome Edge Firefox Internet Explorer Opera Safari
@@species 51 79 48 No 38 10
Mobile
Android webview Chrome for Android Firefox for Android Opera for Android Safari on iOS Samsung Internet
@@species 51 51 48 41 10 5.0
Server
Node.js
@@species 6.5.0
6.5.0
6.0.0
Disabled
Disabled From version 6.0.0: this feature is behind the --harmony runtime flag.

See also

© 2005–2018 Mozilla Developer Network and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://wiki.developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/@@species