OOP Studio Ages 9-15

Inheritance

Students learn how one class can extend another class and add its own special behavior.

15-20 min Ages 9-15 OOP JavaScript

Inheritance

Inheritance is a family tree for classes. The parent class teaches the basics — every GameCharacter can introduce itself. A child class extends the parent: a Wizard gets everything a GameCharacter has, plus its own spell.

1

The parent teaches the basics

class GameCharacter handles what EVERY character needs — a name and introduce(). Write it once, up at the top of the family tree.
2

extends = "is a kind of"

class Wizard extends GameCharacter means a Wizard is a GameCharacter. It inherits introduce() for free and adds its own castSpell().
3

Try it

Add a Knight extends GameCharacter with a swingSword() method. Both children can introduce themselves — neither had to re-learn it.

Code Editor

Make a special kind of object.

Example code

class GameCharacter {
  constructor(name) {
    this.name = name;
  }

  introduce() {
    say("I am " + this.name + ".");
  }
}

class Wizard extends GameCharacter {
  castSpell() {
    say(this.name + " casts a sparkle spell!");
  }
}

let hero = new Wizard("Nova");
hero.introduce();
hero.castSpell();

Output

Program result

Type real JavaScript, then run it.

Inheritance

Inheritance

The parent teaches the basics

extends = "is a kind of"

Try it

Make a special kind of object.

Program result

`extends` = "is a kind of"