Concept of Overloading and Overriding in c#

Concept of Overloading and Overriding in c#

Concept of overloading and overriding is very confusing for beginner. They are very familiar with two terms but don’t know exact difference between them. If you are in same category then this article is for you. Here we will try to understand the concept of overloading and overriding with very simple example.

Before going to discussion we will clear basic concept of them.

Overloading: -  Function name is same but argument set is different and all functions are within same class.

Overriding:- Function name is same function argument is same but functions are in different class. And one class must be derive from other class.

Example of overloading

As per definition, function argument set must be different but function name will be same and functions are in same class. In below example, we have implemented simple overloading concept within Myclass class. Here we are overloading Print() function. If you observe body of Myclass class you will find three different signature of Print() function where function name is same but argument type and number are different. And according to passing argument type and number the appropriate function will invoke.

using System;
using System.Collections;
using System.Data.SqlClient;
using System.Threading;
using System.Data.Common;
using System.Data;
using System.Reflection;
using System.Globalization;
namespace Test1
{
    class MyClass
    {
        public void Print()
        {
            Console.WriteLine("sourav Kayal");
        }
        public void Print(String name)
        {
            Console.WriteLine(name + " Kayal");
        }
        public void Print(String name, String surname)
        {
            Console.WriteLine(name + surname);
        }
     }
    
 
    class Program
    {
        static void Main(string[] args)
        {
            MyClass obj = new MyClass();
           
	obj.Print();
           
	obj.Print("Sourav");
           
	obj.Print("Sourav"," Kayal");
 
            Console.ReadLine();
        }
    }
}

Example of overriding

using System;
using System.Collections;
using System.Data.SqlClient;
using System.Threading;
using System.Data.Common;
using System.Data;
using System.Reflection;
using System.Globalization;
namespace Test1
{
    class BaseClass
    {
        public virtual void Hello()
        {
            Console.WriteLine("I am base hello");
        }
    }
    class DeriveClass : BaseClass
    {
        public override void Hello()
        {
            //base.Hello();
            Console.WriteLine("I am derive hello function");
        }
    }
 
    class Program
    {
        static void Main(string[] args)
        {
            DeriveClass objD = new DeriveClass();
           
            objD.Hello();   //Call Hello function of derived class
            Console.ReadLine();
        }
    }
}

In function definition of base class we have to use virtual keyword and in derive class definition we have to use override keyword.