Introduction to Object-Oriented Systems

Introduction to Object-Oriented Systems

·       A software design and development approach.

·       Uses "objects"à represent data and the operations (methods) à operation perform on that data.

·       Modular,

·       Reusable,

·       Easier to design complex applications.

 

Core Concepts or key features of Object-Oriented Systems

1. Objects:
• fundamental building blocksà representsà  an instance of a class, à created by the class
• An object has two primary attributes:
• State (Attributes/Properties/ data):
• Behaviour (Methods/Functions):

Example:- car object:

• State: colour, model, speed, engine status
• Behaviour: start(), stop(), accelerate()
1. Classes:
• Templates or blueprintsà define the properties and methodsà used for creating objects.
2. Encapsulation:
• Concept of bundling data and the methodsà that operate on that data into a single unit, i.e., a class.
3. Inheritance:
• A mechanism à one class to inherit properties and behaviours from another class.

example:

• A Vehicle class is a superclass, and a Car class inherit from it.
4. Polymorphism:
• Different objects respond to the same method or function call in different ways.
• Multiple features work by one method name.
5. Abstraction:
• A concept à hiding complex implementation details and exposing only the necessary and relevant parts of an object.

7.     Constructors and Destructors:

• Constructors: Special methods used to initialise objects when they are created.
• Destructors: Methods that clean up resources when an object is destroyed.
7. Interfaces and Abstract Classes:
• Interface: A contract that defines methods that classes must implement, providing a way for unrelated classes to communicate.
• Abstract Class: A class that cannot be instantiated but provides a common interface for subclasses.

 

Advantages of Object-Oriented Systems

1. Modularity:
2. Reusability:
3. Scalability:
4. Maintainability:
5. Real-World Modelling:
6. Security:

 

Disadvantages of Object-Oriented Systems

1. Complexity:
• For beginners, due to concepts like classes, inheritance, and polymorphism, etc.
2. Performance Overhead:
• additional memory and processing overhead à due to object creation, inheritance, and method calls.
3. Longer Development Time:
• especially for large and complex systems.
4. Overhead of Abstraction:
• increased complexity à make the code harder to maintain or understand.

Examples

1. Java:
2. C++:
3. Python:
4. C#:
5. Ruby:

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