Introduction to Object-Oriented Programming -2 Inheritance & Polymorphism

In this article, we will continue to tackle Object-Oriented Programming- abbr. OOP-. The topics of this article are Inheritance and Polymorphism. These topics are two of the primary characteristics of object-oriented programming.

• Inheritance enables you to create new classes that reuse, extend, and modify the behavior defined in other classes.
• Polymorphism is a Greek word that means “many-shaped”. And it occurs when we have many classes that are related to each other by inheritance.

Inheritance

Inheritance is a concept in which you define parent classes and child classes. So, It is the mechanism by which one class is allowed to inherit the features (fields and methods) of another class. Inheritance gives us reusability. Reusability could be described as creating a new class by reusing the properties of the existing class.

We define the “inheritance concept” into two categories:

• Derived Class (child) — the class that inherits from another class
• Base Class (parent) — the class being inherited from

C#

class BaseClass
{
 public string model { get; set; }
 public string color { get; set; }
 public void TurnOn() 
 {
  Console.WriteLine("Turn On");
 }
 public void TurnOff() 
 {
  Console.WriteLine("Turn Off");
 }
}

class MacBook : BaseClass
{
 public string display { get; set; }
 public string storage { get; set; }
 public void OpenTerminal() { 
  Console.WriteLine("Terminal Opened"); 
 }
}

class Phone : BaseClass
{
 public string capacity { get; set; }
 public string display { get; set; }
 public void Call(string phoneNumber) 
 {
  Console.WriteLine(phoneNumber + " Calling ");  
 }
}

MacBook macBook = new MacBook();
macBook.model = "MacBook Pro";
macBook.color = "Space Gray";
macBook.display = "13";
macBook.storage = "1 TB";
macBook.TurnOn(); // Turn On

Phone phone = new Phone();
phone.model = "Iphone 12";
phone.color = "Pasific Blue";
phone.capacity = "256 GB";
phone.display = "6.1";
phone.TurnOn(); // Turn On
phone.Call("+90 242 242 2424");// "+90 242 242 2424 Calling"

JavaScript (ES6)

class BaseClass {
  constructor(model, color) {
    this.model = model;
    this.color = color;
  }
  TurnOn() {
    return "Turn On";
  }
  TurnOff() {
    return "Turn Off";
  }
}