This is a new technology, part of the ECMAScript 2015 (ES6) standard .
This technology's specification has been finalized, but check the compatibility table for usage and implementation status in various browsers.
The static keyword defines a static method for a class.
Syntax
static methodName() { ... }
Description
Static methods are called without instantiating their class and are also not callable when the class is instantiated. Static methods are often used to create utility functions for an application.
Examples
The following example demonstrates several things. It shows how a static method is implemented on a class and that a class with a static member can be subclassed. Finally it shows that how a static method can and cannot be called.
class Tripple {
static tripple(n) {
n = n | 1;
return n * 3;
}
}
class BiggerTripple extends Tripple {
static tripple(n) {
return super.tripple(n) * super.tripple(n);
}
}
console.log(Tripple.tripple());
console.log(Tripple.tripple(6));
console.log(BiggerTripple.tripple(3));
var tp = new Tripple();
console.log(tp.tripple()); //Logs 'tp.tripple is not a function'.
Specifications
| Specification | Status | Comment |
|---|---|---|
| ECMAScript 2015 (6th Edition, ECMA-262) The definition of 'Class definitions' in that specification. |
Standard | Initial definition. |
Browser compatibility
| Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
|---|---|---|---|---|---|
| Basic support | 42.0 | Nightly build | ? | ? | ? |
| Feature | Android | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile | Chrome for Android |
|---|---|---|---|---|---|---|
| Basic support | Not supported | Nightly build | ? | ? | ? | 42.0 |