JS/TS OOP Course: 1-Introduction

Introduction

OOP stands for Object Oriented Programming, it is programming paradigm that is used to structure a software app into simple, reusable pieces of code blueprints (usually called classes), which are used to create individual instances of objects.

OOP In Javascript

Javascript is a multi-paradigm language, meaning that it supports multiple programming paradigms. One of the paradigms that Javascript supports is OOP.

Classes was firstly introduced in ES6, it was improved and made more powerful.

OOP Before ES6

Before ES6 Classes, Javascript had a prototype-based inheritance, which is a pattern that uses prototypal inheritance to build up inheritance hierarchies.

For example, A class like this in ES6:

class Person {
  constructor(name, age) {
    this.name = name;
    this.age = age;
  }

  greet() {
    console.log(`Hello, my name is ${this.name} and I am ${this.age}`);
  }
}

Is equivalent to this in ES5:

function Person(name, age) {
  this.name = name;
  this.age = age;
}

Person.prototype.greet = function () {
  console.log(`Hello, my name is ${this.name} and I am ${this.age}`);
};

But we can't really say this is a formal OOP structure, that's why i consider real OOP to be introduced in ES6.

What we'll cover in this course

In this course, we'll cover the following topics:

Classes
Objects
Constructors
Class Members
Static And Non-Static Members
Methods
Properties
Getters And Setters
Static Methods
Inheritance
Abstract Classes
Access Modifiers
Interfaces
Polymorphism
Encapsulation
Composition
Aggregation
SOLID Principles
Coupling And Cohesion

So in the previous list, there are two things, OOP principles and OOP concepts, we'll see it in depth for each single topic of the list.

What about Design Patterns?

Design patterns are not part of the OOP paradigm, but they are very useful in OOP. We'll cover them in a separate course.

Sometimes they are also called Object-Oriented Design or OOD for short.

Hint about this course

I will try to make this course more simpler, which means it will not be an academic course, but all the concepts will be explained in a simple way, so that you can understand them easily, and i'll provide a real world examples for each topic.

So you'll not see a lot of talking here, simple words and definitions will be the Dominator here.