Classes and Objects Explained

In C#, classes and objects are fundamental concepts of object-oriented programming (OOP). Understanding these concepts is crucial for building modular and reusable code. Let's delve into the key concepts related to classes and objects.

1. Classes

A class is a blueprint or template for creating objects. It defines the properties (attributes) and behaviors (methods) that the objects of the class will have. A class encapsulates data and functions into a single unit, making it easier to manage and reuse code.

Example of a Class

class Car
{
    // Properties
    public string Make;
    public string Model;
    public int Year;

    // Methods
    public void StartEngine()
    {
        Console.WriteLine("Engine started.");
    }

    public void StopEngine()
    {
        Console.WriteLine("Engine stopped.");
    }
}

In this example, the Car class has three properties: Make, Model, and Year. It also has two methods: StartEngine and StopEngine.

2. Objects

An object is an instance of a class. When a class is defined, only the specification for the object is defined; no memory or storage is allocated. Objects are created using the new keyword, which allocates memory for the object and initializes its properties.

Example of Creating an Object

Car myCar = new Car();
myCar.Make = "Toyota";
myCar.Model = "Camry";
myCar.Year = 2020;

myCar.StartEngine();  // Output: Engine started.
myCar.StopEngine();   // Output: Engine stopped.

In this example, myCar is an object of the Car class. The properties Make, Model, and Year are set, and the methods StartEngine and StopEngine are called.

3. Encapsulation

Encapsulation is the process of bundling the data (properties) and methods (functions) that operate on the data into a single unit (class). It also involves restricting access to some of the object's components, which helps in controlling the modification of data.

Example of Encapsulation

class BankAccount
{
    private double balance;

    public void Deposit(double amount)
    {
        if (amount > 0)
        {
            balance += amount;
        }
    }

    public void Withdraw(double amount)
    {
        if (amount > 0 && amount <= balance)
        {
            balance -= amount;
        }
    }

    public double GetBalance()
    {
        return balance;
    }
}

In this example, the balance property is private, meaning it cannot be accessed directly from outside the class. The methods Deposit, Withdraw, and GetBalance provide controlled access to the balance.

Conclusion

Classes and objects are the building blocks of object-oriented programming in C#. Classes define the blueprint for objects, while objects are instances of those classes. Encapsulation ensures that data and methods are bundled together and accessed in a controlled manner. By understanding these concepts, you can create more modular, reusable, and maintainable code.