C# Inheritance with Examples

 

In c#, Inheritance is one of the primary concepts of object-oriented programming (OOP), and it is used to inherit the properties from one class (base) to another (child) class.

 

The inheritance will enable us to create a new class by inheriting the properties from other classes to reuse, extend, and modify other class members' behavior based on our requirements.

 

In c# inheritance, the class whose members are inherited is called a base (parentclass, and the class that inherits the members of the base (parent) class is called a derived (childclass.

C# Inheritance Syntax

Following is the syntax of implementing an inheritance to define a derived class that inherits the base class's properties in the c# programming language.

 

<access_modifier> class <base_class_name>
{
// Base class Implementation
}

<access_modifier> class <derived_class_name> : <base_class_name>
{
// Derived class implementation
}

If you observe the above syntax, we are inheriting the base class's properties into the child class to improve code reusability.

 

Following is the simple example of implementing inheritance in the c# programming language.

 

public class X
{
    public void GetDetails()
    {
       // Method implementation
    }
}
public class Y: X
{
    // your class implementation
}
class Program
{
   static void Main(string[] args)
   {
       Y y = new Y();
       y.GetDetails();
   }
}

If you observe the above example, we defined a class “X” with the method called “GetDetails” and the class “Y” is inheriting from class “X”. After that, we call a “GetDetails” method by using an instance of derived class “Y”.

 

In c#, it’s not possible to inherit the base class constructors in the derived class. The accessibility of other base class members also depends on the access modifiers that we used to define those members in a base class.

C# Inheritance Example

Following is the example of implementing an inheritance by defining two classes in the c# programming language.

 

using System;

namespace Tutlane
{
    public class User
    {
       public string Name;
       private string Location;
       public User()
       {
          Console.WriteLine("Base Class Constructor");
       }
       public void GetUserInfo(string loc)
       {
          Location = loc;
          Console.WriteLine("Name: {0}", Name);
          Console.WriteLine("Location: {0}", Location);
       }
    }
    public class Details: User
    {
       public int Age;
       public Details()
       {
          Console.WriteLine("Child Class Constructor");
       }
       public void GetAge()
       {
          Console.WriteLine("Age: {0}", Age);
       }
    }
    class Program
    {
       static void Main(string[] args)
       {
          Details d = new Details();
          d.Name = "Suresh Dasari";
          // Compile Time Error
          //d.Location = "Hyderabad";
          d.Age = 32;
          d.GetUserInfo("Hyderabad");
          d.GetAge();
          Console.WriteLine("\nPress Any Key to Exit..");
          Console.ReadLine();
       }
    }
}

If you observe the above example, we defined a base class called “User” and inheriting all the user class properties into a derived class called “Details” and we are accessing all the members of the User class with an instance of the Details class.

 

If we uncomment the commented code, we will get a compile-time error because the Location property in the User class is defined with a private access modifier. The private members can be accessed only within the class.

 

When you execute the above c# program, you will get the result as shown below.

 

C# Inheritance Example Result

 

If you observe the above result, we are able to access all the properties of base class into child class based on our requirements.

 

 In c#, Structures won’t support inheritance, but they can implement interfaces.

C# Multi-Level Inheritance

Generally, c# supports only single inheritance that means a class can only inherit from one base class. However, in c# the inheritance is transitive, and it allows you to define a hierarchical inheritance for a set of types, and it is called a multi-level inheritance.

 

For example, if class C is derived from class B, and class B is derived from class A, then class C inherits the members declared in both class B and class A.

 

public class A
{
// Implementation
}
public class B: A
{
// Implementation
}
public class C: B
{
// Implementation
}

If you observe the above code snippet, class C is derived from class B, and class B is derived from class A, then class C inherits the members declared in both class B and class A. This is how we can implement multi-level inheritance in our applications.

C# Multi-Level Inheritance Example

Following is the example of implementing multi-level inheritance in the c# programming language.

 

using System;

namespace Tutlane
{
    public class A
    {
       public string Name;
       public void GetName()
       {
          Console.WriteLine("Name: {0}", Name);
       }
    }
    public class B: A
    {
       public string Location;
       public void GetLocation()
       {
          Console.WriteLine("Location: {0}", Location);
       }
    }
    public class C: B
    {
       public int Age;
       public void GetAge()
       {
          Console.WriteLine("Age: {0}", Age);
       }
    }
    class Program
    {
       static void Main(string[] args)
       {
          C c = new C();
          c.Name = "Suresh Dasari";
          c.Location = "Hyderabad";
          c.Age = 32;
          c.GetName();
          c.GetLocation();
          c.GetAge();
          Console.WriteLine("\nPress Any Key to Exit..");
          Console.ReadLine();
       }
    }
}

If you observe the above example, we implemented three classes (A, B, C), and class C is derived from class B, and class B is derived from class A.

 

By implementing a multi-level inheritance, class C can inherit the members declared in class B and class A.

 

When you execute the above c# program, you will get the result as shown below.

 

C# Multilevel Inheritance Example Result

C# Multiple Inheritance

As discussed, c# supports only single inheritance that means a class can only inherit from one base class. If we try to inherit a class from multiple base classes, then we will get compile-time errors.

 

For example, if class C is trying to inherit from Class A and B simultaneously, we will get a compile-time error because multiple inheritance is not allowed in c#.

 

public class A
{
// Implementation
}
public class B
{
// Implementation
}
public class C: A, B
{
// Implementation
}

If you observe the above code snippet, class C is trying to inherit properties from both classes A and B simultaneously, which will lead to compile-time errors like “Class C cannot have multiple classes: A and B”.

 

As discussed, multi-level inheritance is supported in c#, but multiple inheritance is not supported. If you want to implement multiple inheritance in c#, we can achieve this by using interfaces. In the next chapters, we will learn how to use interfaces to achieve multiple inheritance in a detailed manner.