Unit 5: Object-Oriented Programming (OOP) (10 Hours)

Unit 5: Object-Oriented Programming (OOP) (10 Hours)

5.1 Programming Paradigms: Procedural, Structural, and Object-Oriented

Programming paradigms are different styles or approaches to programming that dictate how solutions are formulated.

• Procedural Programming:
  • Based on the concept of procedure calls.
  • Emphasizes functions or procedures to operate on data.
  • Example languages: C, Pascal.
  • Advantages: Simplicity and ease of understanding; good for small programs.
• Structural Programming:
  • An extension of procedural programming.
  • Focuses on improving the clarity and efficiency of code by using structures (such as control flow structures).
  • Encourages breaking programs into smaller, manageable pieces.
  • Example languages: C, Ada.
• Object-Oriented Programming:
  • Organizes software design around data (objects) rather than functions and logic.
  • Promotes concepts such as encapsulation, inheritance, and polymorphism.
  • Example languages: C++, Python.
  • Advantages: Improved code reusability, scalability, and maintainability.

5.2 Features of OOP: Class, Object, Polymorphism, and Inheritance

OOP is characterized by several key features:

• Class:

  • A blueprint for creating objects.
  • Encapsulates data for the object and methods to manipulate that data.
  • Example in C++:

    cpp
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    class Car {
    public:
        string color;
        string model;
        
        void displayInfo() {
            cout << "Model: " << model << ", Color: " << color << endl;
        }
    };
    

• Object:

  • An instance of a class.
  • Contains real values instead of variables.
  • Example:

    cpp
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    Car myCar; // myCar is an object of class Car
    myCar.color = "Red";
    myCar.model = "Toyota";
    myCar.displayInfo(); // Output: Model: Toyota, Color: Red
    

• Polymorphism:

  • The ability to present the same interface for different data types.
  • Achieved through:
    • Method Overloading: Multiple functions with the same name but different parameters.

      cpp
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      class Math {
      public:
          int add(int a, int b) {
              return a + b;
          }
          double add(double a, double b) {
              return a + b;
          }
      };
      

    • Method Overriding: A derived class provides a specific implementation of a method already defined in its base class.

      cpp
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      class Animal {
      public:
          virtual void sound() { cout << "Animal sound"; }
      };
      
      class Dog : public Animal {
      public:
          void sound() override { cout << "Bark"; }
      };
      

• Inheritance:

  • Mechanism by which one class (derived class) can inherit the attributes and methods of another class (base class).
  • Types of inheritance:
    • Single Inheritance: One derived class inherits from one base class.
    • Multiple Inheritance: One derived class inherits from multiple base classes.
    • Multilevel Inheritance: A class is derived from another derived class.
    • Hierarchical Inheritance: Multiple classes are derived from the same base class.
  • Example:

    cpp
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    class Vehicle { // Base class
    public:
        void start() { cout << "Starting vehicle"; }
    };
    
    class Car : public Vehicle { // Derived class
    public:
        void honk() { cout << "Car honks"; }
    };
    

5.3 Advantages of OOP

• Modularity: Code is organized into discrete classes and objects, enhancing clarity and organization.
• Reusability: Classes and objects can be reused across different programs, saving time and effort.
• Maintainability: Easier to update and maintain code due to modular design.
• Abstraction: Hides complex implementation details and exposes only the necessary features to the user.
• Inheritance: Facilitates code reuse and extension through derived classes.

5.4 Applications of OOP

OOP is widely used across various domains due to its flexibility and effectiveness. Some applications include:

• Software Development: Used in creating desktop applications, mobile apps, and web applications.
• Game Development: Helps in modeling complex interactions between game objects.
• Simulation and Modeling: Useful in scientific computing, simulations, and modeling real-world systems.
• Database Management: Facilitates the design of object-oriented databases that model complex data relationships.