Types of Inheritance In C#

Inheritance in C#

Inheritance is one of the key features of OOPs, and C# language is a modern object-oriented programming language. This article teaches you the basics of inheritance, types of inheritance, and how to implement inheritance in C#. 

What is Inheritance 

Acquiring (taking) the properties of one class into another is called inheritance. Code reusability is one of the key features of OOPs, and it is achieved via inheritance. Using inheritance, one or more classes can derive from an existing class. The existing class is called a base class, and the inherited class is called a derived or inherited class. 

The following are the types of inheritance in C#.

The inheritance concept is based on a base class and its derived classes. Let us see the definition of base and derived classes. 

• Base class - the class from which features are to be inherited into another class.
• Derived class - the class that is inherited from the base class.

Single inheritance in C#

It is the type of inheritance in which there is one base class and one derived class. 

For example,

public class Accountcreditinfo //base class    
{  
    public string Credit()  
    {  
        return "balance is credited";  
    }  
}  
public class debitinfo : Accountcreditinfo //derived class    
{  
    public string debit()  
    {  
        Credit();                       ////derived class method    
        return "balance is debited";  
    }  
}

In the preceding sample program, Accountcreditinfo is the base class, and debitinfo is the derived class.

Hierarchical inheritance in C#

This is the type of inheritance in which there are multiple classes derived from one base class. This type of inheritance is used when there is a requirement of one class feature that is needed in multiple classes.

For example,

class A  //base class    
{  
    public string msg()  
    {  
        return "this is A class Method";  
    }  
}  
class B : A  
{  
    public string info()  
    {  
        msg();  
        return "this is B class Method";  
    }  
    class C : A  
    {  
        public string getinfo()  
        {  
            msg();  
            return "this is B class Method";  
        }  
    }  
}

In the preceding program, one base class is derived from many classes; hence it is called a Hierarchical Inheritance.

Multilevel inheritance in C#

When one class is derived from another, this type of inheritance is called multilevel inheritance.

For example,

public class Person  
{  
    public string persondet()  
    {  
        return "this is the person class";  
    }  
}  
public class Bird : Person  
{  
    public string birddet()  
    {  
        persondet();  
        return "this is the birddet Class";  
    }  
}  
public class Animal : Bird  
{  
    public string animaldet()  
    {  
        persondet();  
        birddet();  
        return "this is the Animal Class";  
    }  
}

In the preceding program, each class is derived from one class that is derived from another class hence this type of inheritance is called Multilevel Inheritance.

Multiple inheritances using Interfaces

C# does not support multiple inheritances of classes. To overcome this problem, we can use interfaces. We will see more about interfaces in my next article in detail.

For example,

public interface IA //ineterface  1    
{  
    string setImgs(string a);  
}  
public interface IB  //Interface 2    
{  
    int getAmount(int Amt);  
}  
public class ICar : IA, IB //implementatin    
{  
    public int getAmount(int Amt)  
    {  
        return 100;  
    }  
    public string setImgs(string a)  
    {  
        return "this is the car";  
    }  
}

In the preceding program, the ICar class inherits the features of the two interfaces; hence this type of inheritance is called Multiple Inheritance.

The following are some key points about inheritance:

1. C# does not support multiple inheritances of classes, the same thing can be done using interfaces.
2. Private members are not accessed in a derived class when one class is derived from another.

Summary

This article taught you the types of inheritance in C#. We saw the fundamental differences between various types of inheritance and how to implement them.

Next readings:

Here are more articles on inheritance and object-oriented programming in C#.

• Multiple Inheritance in C#
• A Complete Guide To Object-Oriented Programming In C# (c-sharpcorner.com)