The Ultimate OOP & Design Patterns Masterguide

Module 01

The 4 Pillars of OOP

description

The Class

The Blueprint / Template

A Class is just code. It describes what an object will look like. It doesn't live in memory until instantiated.

class CyberDroid {
  constructor(name, color) {
    this.name = name;
    this.color = color;
  }
}

smart_toy

The Object

The Instance / Actual Entity

Memory Empty

Module 02

Encapsulation vs Abstraction

Often confused, these two concepts work together to manage complexity and security. Use the interactive model below to see the difference.

Hover cards to visualize logic

touch_app

1. Abstraction (The Interface)

You press "Brew". You don't know about water pressure or circuits. Abstraction hides complexity and shows only what's necessary.

lock

2. Encapsulation (The Protection)

The casing protects the wires. You cannot touch the heater directly. Encapsulation protects data integrity by bundling it and restricting access.

terminal Code Lab

// ✅ ABSTRACTION: Simple Interface
class Wallet {
  buyItem(price) {
    // Internal complex tax logic hidden
    const tax = this.#calcTax(price);
    this.#balance -= (price+tax);
  }
}

Step 2: Abstraction

The user just calls `buyItem()`. They don't need to know about tax calculations occurring internally.

> Item Purchased! (Tax calc hidden)

Module 03

OOP Design Patterns

Reusable solutions to architectural problems.

Structural

Facade

Simplified interface

error The Problem

Complex system requires 10 steps to initialize.

check_circle The Solution

Create a class with one simple method that handles the 10 steps internally.

implementation.js

class VideoFacade {
  convert() {
    file.load();
    codec.init();
    // ...
  }
}

Module 04

Knowledge Check

Test your understanding of OOP concepts and Design Patterns.

quiz

Ready to Start?

There are 18 questions. Try to get a perfect score!

Object-Oriented Mastery

What is an OOP Concept?

What is a Design Pattern?