[TypeScript] Sharing Class Behavior with Inheritance in TypeScript

Posted 2020-08-14 Answer1215

Typescript classes make inheritance much easier to write and understand. In this lesson we look into how to set up inheritance with Typescript classes, extends and super.

 

class ComicBookCharacter (
  constructor{
    public alias: string, public health: number , public strength: number,
    protected secretIdentity: string
  ) {}
}

class SuperVillain extends ComicBookCharacter {
  flaws = ["hubris", "always explains evil plan"];

  constructor(a, b, c, d) {
    console.log(‘${this.alias} eats kittens!!!‘);
    super(a, b, c, d);
  }  
}

 

To review, we can set up inheritance with the extends keyword. The protected access modifier can‘t be accessed outside of a class just like the private access modifier, but it can be accessed in derived classes.

If you don‘t define a constructor, the derived class will use the base class‘s constructor. If you do define the constructor in a derived class, super must be called before anything else can happen.