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🧬 Inheritance (Basic)

Building a class hierarchy with multiple levels

What Is Inheritance?

Inheritance is an object‑oriented programming feature that lets one class build on top of another.

It allows you to create:

  • A base class (general)
  • One or more subclasses (more specific)
  • Additional subclasses that extend those subclasses (even more specific)

This forms a class hierarchy.

Why Use Inheritance?

Inheritance helps you:

  • Avoid repeating code
  • Share common behavior across many classes
  • Organize your game objects logically
  • Build more complex systems from simple foundations

It’s one of the core pillars of object‑oriented programming.

Example Hierarchy

A common pattern in games is:

GameObject → Character → Player

GameObject

The most general class.
Everything in the game world is a GameObject.

It might define:

  • Position
  • Size
  • Update logic

Character (inherits from GameObject)

A more specific type of GameObject.

It might add:

  • Health
  • Movement
  • Collision behavior

Player (inherits from Character)

A specific type of Character controlled by the user.

It might add:

  • Input handling
  • Inventory
  • Abilities

Example Code (Simple & Clear)

// Base class: the most general object
class GameObject {
    constructor(x, y) {
        this.x = x;
        this.y = y;
    }
}

// Level 2: a character that exists in the world
class Character extends GameObject {
    constructor(x, y, health) {
        super(x, y);
        this.health = health;
    }
}

// Level 3: a specific type of character
class Player extends Character {
    constructor(x, y, health, name) {
        super(x, y, health);
        this.name = name;
    }
}

This demonstrates:

  • 2+ levels of inheritance
  • A clear hierarchy
  • How each class becomes more specific

Why?

Creating a class hierarchy shows that you understand:

  • How to structure code from general → specific
  • How to reuse behavior through inheritance
  • How to design scalable game systems
  • How to think in terms of object families

It’s a foundational skill in object‑oriented programming and game development.