javascript - Is there a way to get name of child class in parent class?

Question

I am trying to print out the name of class B or C in it's super class (A). Is there a way to infer this somehow from the context? Do I have to pass in the names into super as a parameter or is there a better way of doing this?

class A {
  constructor(){
    console.log(klass_name) // klass_name is some code to get the name of class B,C
  }
}

class B extends A {
  constructor() {
    super();
  }
}

class c extends A {
  super();
}

Answer 1

Yes, there are two ways you can access it where you've shown:

• this.constructor.name (assuming nothing has messed around with it), which you can use anywhere that has access to the instance
• new.target.name (only available in the constructor, new.target is undefined in function calls that aren't part of a new operation)

But other than logging purposes and such, it's rare for the superclass to need to know anything about the subclass.

Example:

class A {
  constructor(){
    console.log("this.constructor.name = " + this.constructor.name);
    console.log("new.target.name = " + new.target.name);
  }
}

class B extends A {
}

class C extends A {
}

new C;