C# inheritance

In C#, inheritance is a mechanism that allows you to create a new class from an existing class, inheriting all of its properties and methods. The new class is called the "derived" class, and the existing class is called the "base" class. Inheritance is a fundamental concept in object-oriented programming, and it helps you to create complex class hierarchies that are easy to understand and maintain.

To create a derived class in C#, you use the : operator to specify the base class, like this:

class DerivedClass : BaseClass
{
    // Derived class members go here
}

The DerivedClass is the new class that you are creating, and BaseClass is the class that you are inheriting from. The members of the base class are automatically inherited by the derived class, and you can access them using the base keyword. You can also add new members to the derived class, including properties, fields, methods, and events.

Here's an example that demonstrates how to create a derived class in C#:

class Shape
{
    protected double width;
    protected double height;

    public void SetWidth(double w)
    {
        width = w;
    }

    public void SetHeight(double h)
    {
        height = h;
    }
}

class Rectangle : Shape
{
    public double GetArea()
    {
        return width * height;
    }
}

In this example, the Shape class is the base class, and the Rectangle class is the derived class. The Rectangle class inherits the width and height fields and the SetWidth and SetHeight methods from the Shape class, and it defines a new GetArea method that calculates the area of the rectangle.

You can create an instance of the Rectangle class and use its methods like this:

Rectangle rect = new Rectangle();
rect.SetWidth(5);
rect.SetHeight(10);
double area = rect.GetArea();

In this example, you create a new instance of the Rectangle class, set its width and height, and calculate its area using the GetArea method. The GetArea method uses the width and height fields inherited from the Shape class to perform the calculation.

Inheritance is a powerful mechanism that allows you to reuse code and create complex class hierarchies in C#. By using inheritance, you can create new classes that are tailored to your specific needs, while still benefiting from the functionality and features of the base class.