Object orientated programming

In the ever-evolving field of computer science, object orientated programming (OOP) has become an essential paradigm to understand and master. This technique revolves around organising code into objects, which represent real-world elements, providing structure and reusability in software development. As you delve into the world of OOP, you will learn the fundamentals of this programming approach and why it's crucial to be well-versed in its principles. Armed with this knowledge, you will explore how popular programming languages like Python and Java utilise OOP concepts like classes, inheritance, and polymorphism to create robust and versatile applications. With practical examples, tips and techniques, you will gain a comprehensive understanding of OOP and its significance in modern computer science.

What is Object Orientated Programming?

Fundamentals of Object Oriented Programming

• Encapsulation
• Inheritance
• Polymorphism
• Abstraction

Importance of Object Oriented Programming Principles

• Modularity
• Code reuse
• Maintainability
• Scalability

Object Oriented Programming with Python

Examples of Python Object Oriented Programming

 class ClassName: # class-level attributes # instance methods

class Person: def __init__(self, name, age): self.name = name self.age = age def greet(self): print(f"Hello, my name is {self.name} and I am {self.age} years old.") 

python person1 = Person("Alice", 30)

 # Accessing attributes print(person1.name) # Output: Alice print(person1.age) # Output: 30 # Calling a method person1.greet() # Output: Hello, my name is Alice and I am 30 years old.

A class is a blueprint for creating objects in Java, encapsulating properties (attributes) and behaviours (methods) that represent a particular entity. Java classes follow a specific structure:

public class ClassName { // attributes // methods } 

To create a new class in Java, use the `public class` keyword followed by the desired class name. For example, let's create a "Circle" class representing a simple geometric shape.

public class Circle { private double radius; public Circle(double radius) { this.radius = radius; } public double getArea() { return Math.PI * Math.pow(radius, 2); } public double getCircumference() { return 2 * Math.PI * radius; } } 

In this example, we define a `Circle` class with a private attribute `radius` and three methods: a constructor for initializing the circle with a specified radius, a `getArea` method for calculating the area of the circle, and a `getCircumference` method for calculating the circumference.

Java classes support encapsulation, allowing you to protect sensitive data and control access to class attributes and methods. For instance, in our `Circle` class, the attribute `radius` is marked as private, which prevents direct access from outside the class. Instead, access is provided through public methods, which define a controlled interface to interact with the class. The combination of Java classes and the core OOP principles enables you to create structured, maintainable, and reusable code.

By leveraging Java's rich Object Oriented Programming capabilities, you can build robust software systems that fulfil your requirements and can adapt to changes without extensive rework.