How to override any method

Overriding helps in new implementation of base class method in the child class. For example, take classes A and B. Class A has method sum which takes two integer parameters and we should override that in the child class.

Base class:
=============
public Class A
{
  public virtual int sum(int a, int b)
{
        return (a+b);
}
}

Child Class inheriting base class:
======================
public class B:A
{
public override int sum(int a, int b)
{
        return (a+b)+50;
}
}

To override a method, first the base class should have a method decorated with virtual keyword. Virtual keyword tells the compiler that the child class is going to override the implementation. Override must be decorated for the method in the child class to inform compiler that we are defining our own implementation in the child class. By default the child class inherit all the properties and methods of the base class and based on the access modifiers can use base class methods.

If you want to call a base class method in child class method you have to refer the base class method by base.sum(4,5). Note the signature and access modifier should be same in both the child class and parent class for overriding.

Let me know if you have any questions.

You can only override virtual or abstract methods. For example: 

   

 

Suppose you have 2 classes say(A and B)

class A
{
        public virtual int Method1()
        {
                int x = 10;
                return x;
        }        
}

class B : A
{
        public override int Method1()
        {
                int y = 20;
                return y;
        }
}

Class B inherits A and the method in the Class A has to be defined with the Virtual keyword.... The Overridden method should have the same method name, return type and the same number of arguments.... Hope this helps you.

Please mark this as Answer if it helps you. Thanks.