Array.@@species

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 over-ride it to change the constructor assignment.

Examples

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

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

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

Specification	Status	Comment
ECMAScript 2015 (6th Edition, ECMA-262) The definition of 'get Array [ @@species ]' in that specification.	Standard	Initial definition.
ECMAScript 2017 Draft (ECMA-262) The definition of 'get Array [ @@species ]' in that specification.	Draft

Browser compatibility

See also

• Array
• Symbol.species