Base class in C#

In C#, a base class is a class that serves as a starting point for other classes that inherit from it. When a class inherits from a base class, it can use all the members (fields, properties, methods, etc.) of the base class as if they were its own.

Here’s an example of a base class in C#:

public class Animal
{
    public int Age { get; set; }
    public string Name { get; set; }

    public void Sleep()
    {
        Console.WriteLine("Zzzzzzz...");
    }

    public void Eat()
    {
        Console.WriteLine("Yum!");
    }
}

In this example, the Animal class is a base class. It contains two properties (Age and Name) and two methods (Sleep and Eat).

To inherit from a base class, we use the : symbol followed by the name of the base class. Here’s an example:

public class Cat : Animal
{
    public void Meow()
    {
        Console.WriteLine("Meow!");
    }
}

In this example, the Cat class inherits from the Animal class. It contains one method (Meow). Because Cat inherits from Animal, it can use the Age, Name, Sleep, and Eat members of the Animal class.

When a class inherits from a base class, it can use the members of the base class directly or override them. Here’s an example:

public class Dog : Animal
{
    public new void Eat()
    {
        Console.WriteLine("Nom nom nom!");
    }
}

In this example, the Dog class also inherits from the Animal class. It contains one method (Eat). However, the Eat method in the Dog class has the new keyword, which means that it overrides the Eat method in the Animal class. When we call the Eat method on a Dog instance, it will use the Eat method from the Dog class instead of the Eat method from the Animal class.

Here are some rules to keep in mind when working with base classes in C#:

1. A class can only inherit from one base class.
2. A base class can be any accessible class or interface.
3. A derived class can use the members of its base class directly, or it can override them.
4. If a derived class overrides a member of its base class, it can use the base keyword to call the original implementation of the member from the base class.
5. A derived class can add new members that are not present in its base class.

In summary, a base class in C# is a class that serves as a starting point for other classes that inherit from it. When a class inherits from a base class, it can use all the members of the base class as if they were its own. By leveraging base classes, we can create more flexible and reusable code that can handle a variety of situations.