How to call a class itself and not its instance in Javascript?

Question

I am class and its subclasses, where I am required to call a static method of a child from the parent. But how can I call the static method without knowing which child?

class Animal{
  static doSomething(){
    //How do i call the static talk here?
    //talk()
  }
}

class Human extends Animal{
  static talk(){
    return 'Hello!'
  }
}

class Dog extends Animal{
  static talk(){
    return 'Bark!'
  }
}

Human.doSomething()

Possible duplicate of [Can I use class variables in the parent class's static methods in ES6?](https://stackoverflow.com/q/47504534/218196) — Felix Kling, Jun 21 '18 at 06:24

score 3 · Answer 1 · answered Jun 21 '18 at 04:38

Just call this.talk() from inside the doSomething static method.

class Animal{
  static doSomething(){
    console.log(this.talk());
  }
}

class Human extends Animal{
  static talk(){
    return 'Hello!'
  }
}

class Dog extends Animal{
  static talk(){
    return 'Bark!'
  }
}

Human.doSomething()

In the context of a static method, this will refer to class object was called on (barring any code to change it).

score 2 · Accepted Answer · answered Jun 21 '18 at 04:38

The calling context is the Human class, and the talk method is a property directly on it, so you simply call this.talk():

class Animal{
  static doSomething(){
    return this.talk();
  }
}

class Human extends Animal{
  static talk(){
    return 'Hello!'
  }
}

class Dog extends Animal{
  static talk(){
    return 'Bark!'
  }
}

console.log(Human.doSomething())

How to call a class itself and not its instance in Javascript?

2 Answers2