Daily Interview Question #5 : What is the difference between “Method Overloading” and “Method Overriding”?

Method overloading	Method overriding
method overloading used to achieve “early binding” or “static binding”.	method overriding used to achieve “late (dynamic) binding” or “runtime polymorphism”.
method overloading means, in a class method can be declared with same method name and with different parameters.	method overriding means, a method defined in base class can be redefined in the derived classes.
method signature (method name + parameter) must be different in method overloading.	method signature must be same in method override.

 

Sample Program:

using system;
using system.collections.generic;
using system.text;

namespace consoleapplicationc
{
    //Base class
    class baseclass
    {
        private int add(int a, int b)
        {
            return a + b;
        }
        // Overload the Above Method
        private float add(float a, float b)
        {
            return a + b;
        }
        // virtual method - Indicates this will be override in Child class
        public virtual string whereiam()
        {
            return "In Base Class";
        }
    }
    // Derived Class
    class derived : baseclass
    {
        // Base class Method Override here
        public override string whereiam()
        {
            return "In Derived Class";
        }
    }
    class program
    {
        static void main(string[] args)
        {
            // Just create base class reference
            baseclass basereference;
            // Create Base class Object
            baseclass baseobj = new baseclass();
            // create object for Derived class
            derived derivedobj = new derived();
            // Base class reference contains derived object
            basereference = derivedobj;
            // Now Derived class method called with base ref
            string strvalue = basereference.whereiam();
            console.writeline(strvalue);
            // Now Base class ref contains base object
            basereference = baseobj;
            string strval = basereference.whereiam();
            console.writeline(strval);
            console.read();
        }
    }
}

Output:
in derived class

in base class