Learn All About Inheritance in C#

class ParentClass
{
    // Class members for ParentClass can be added here.
}
class ChildClass : ParentClass
{
    // Class members for ChildClass can be added here.
}

class ParentClass  
{  
    public void Run()  
    {  
        Console.WriteLine("This is parent’s Run method");  
    }  
    public void Walk()  
    {  
        Console.WriteLine("This is parent’s Walk method");  
    }  
}  
class ChildClass : ParentClass  
{  
    public void Eat()  
    {  
        Console.WriteLine("This is the child’s Eat Method");  
    }  
}

Example

The following example shows how to derive a class from multiple classes.

using System;
class ParentClass
{
    public void Run()
    {
        Console.WriteLine("This is parent’s Run method");
    }
    public void Walk()
    {
        Console.WriteLine("This is parent’s Walk method");
    }
}
class ChildClass : ParentClass
{
    public void Eat()
    {
        Console.WriteLine("This is the child’s Eat Method");
    }
}
class SecondChildClass: ChildClass
{
    public void See()
    {
        // Add implementation for the See method if needed.
    }
}

From the above source code, you can see that we have achieved multilevel Inheritance by implementing one derived class into another derived class.

Multiple Inheritance in C#

C# does not support multiple inheritance due to the complexity of a code, and it creates the diamond structure, which creates ambiguity.

Hierarchical Inheritance in C#

When we create a structure of a project like that where more than one derived class is implemented from the same parent class or base class, then that type of implantation is known as hierarchical inheritance.

In short, it means a single base class having more than two or more derived classes.

using System;
class ParentClass
{
    public void Run()
    {
        Console.WriteLine("This is parent’s Run method");
    }
    public void Walk()
    {
        Console.WriteLine("This is parent’s Walk method");
    }
}
class ChildClass : ParentClass
{
    public void Eat()
    {
        Console.WriteLine("This is the child’s Eat Method");
    }
}
class SecondChildClass : ParentClass
{
    public void See()
    {
        // Add implementation for the See method if needed.
    }
}

Here you can see that above the code, the base class BaseClass and two derived classes, childClass and SecondChildClass, are implemented from the same base class i.e.BaseClass.

As you see, we have two derived classes implemented from the same base class. This type of implementation can also be called Hierarchical Inheritance.

Advantages of Inheritance

1. It reduces code redundancy.
2. It provides code reusability.
3. Reduces source code size and improves code readability.
4. After using this code is easy to manage and divided into parent and child classes.
5. It supports code extensibility by overriding the base class functionality within child classes.

Disadvantages of Inheritance

1. In Inheritance, base class and child classes are tightly coupled. Hence, If you change the parent class's code, it will affect all the child classes.
2. Many data members remain unused in the class hierarchy, and the memory allocated is not utilized. Hence affects the performance of your program if you have not implemented inheritance correctly.

Summary

In this article, you learned about inheritance and why we use inheritance in C#.

Next recommended readings

• Types of Inheritance in C#
• 11 Code Examples of Inheritance in C#
• Multiple Inheritance in C#