static

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 how a static method can and cannot be called.

class Triple {
  static triple(n) {
    n = n || 1; //should not be a bitwise operation 
    return n * 3;
  }
}

class BiggerTriple extends Triple {
  static triple(n) {
    return super.triple(n) * super.triple(n);
  }
}

console.log(Triple.triple());        // 3
console.log(Triple.triple(6));       // 18
console.log(BiggerTriple.triple(3)); // 81
var tp = new Triple();
console.log(BiggerTriple.triple(3)); // 81 (not affected by parent's instantiation)
console.log(tp.triple());            // 'tp.triple is not a function'.

Specifications

Browser compatibility

See also

• class expression
• class declaration
• Classes