The Set[@@species]
accessor property returns the Set
constructor.
Set[Symbol.species]
The species accessor property returns the default constructor for Set
objects. Subclass constructors may over-ride it to change the constructor assignment.
The species property returns the default constructor function, which is the Set
constructor for Set
objects:
Set[Symbol.species]; // function Set()
In a derived collection object (e.g. your custom set MySet
), the MySet
species is the MySet
constructor. However, you might want to overwrite this, in order to return parent Set
objects in your derived class methods:
class MySet extends Set { // Overwrite MySet species to the parent Set constructor static get [Symbol.species]() { return Set; } }
Specification | Status | Comment |
---|---|---|
ECMAScript 2015 (6th Edition, ECMA-262) The definition of 'get Set [ @@species ]' in that specification. | Standard | Initial definition. |
ECMAScript Latest Draft (ECMA-262) The definition of 'get Set [ @@species ]' in that specification. | Living Standard |
Feature | Chrome | Edge | Firefox | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|---|
Basic support | 51 | 13 | 41 | No | 38 | 10 |
Feature | Android webview | Chrome for Android | Edge mobile | Firefox for Android | IE mobile | Opera Android | iOS Safari |
---|---|---|---|---|---|---|---|
Basic support | 51 | 51 | 13 | 41 | No | 38 | 10 |
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https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Set/@@species