get Map[@@species]
The Map[@@species]
accessor property returns the Map
constructor.
Description
The species accessor property returns the default constructor for Map
objects.
Subclass constructors may over-ride it to change the constructor assignment.
Examples
Species in ordinary objects
The species property returns the default constructor function, which is the
Map
constructor for Map
objects:
Map[Symbol.species]; // function Map()
Species in derived objects
In a derived collection object (e.g. your custom map MyMap
), the MyMap
species is the MyMap
constructor. However, you might want to overwrite this,
in order to return parent Map
objects in your derived class methods:
class MyMap extends Map {
// Overwrite MyMap species to the parent Map constructor
static get [Symbol.species]() { return Map; }
}
Specifications
Specification |
---|
ECMAScript Language Specification # sec-get-map-@@species |
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