OOP Principles

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Object Oriented Programming, OOP

The purpose of OOP:

• To create understandable, readable, and testable code that many developers can collaboratively work on

Properties of OOP:

1. Abstraction:

• aims to hide complexity from users and show them only relevant information
• For an example, when you are driving a car, you don't need to know about the engines and the internal workings.

2. Encapsulation:

• Helps with data security; allows you to protect the data stored in a class from system-wide access

3. Inheritance:

• Makes it possible to create a child class that inherits the fields and methods of the parent class
• The child class can override the values and methods of the parent class; it can also add new data and functionality to its parent
• Parent class = superclass, base class
• Child class = subclass, derived class

4. Polymorphism:

• Refers to the ability to perform a certain action in different ways
• In Java, there are two forms: method overloading and method overriding
• Method overloading: happens when various methods with the same name are present in a class. They are differentiated by the number, order, or types of their parameters
• Method overriding: occurs when a child class overrides a method of its parent

Source

[sophryu99]

SOLID Principles

The Single Responsibility Principle
The Open-Closed Principle
The Liskov Substitution Principle
The Interface Segregation Principle
The Dependency Inversion Principle

The Single Responsibility Principle

• A class should do one thing and therefore it should have only a single reason to change
• Only one potential change in the software's specification should be able to affect the specification of the class
• Adv1: When different teams work on the same project and edit the same class for different reasons, this could lead to incompatible modules. SRP prevents this.
• Adv2: Makes version control easier. Fewer merge conflicts.