Polymorphism in .Net

http://dotnetguts.blogspot.in/2007/07/example-of-polymorphism-in-net.html

Example of Polymorphism in .Net

What is Polymorphism?Polymorphism means same operation may behave differently on different classes.
- Compile Time Polymorphism: Method Overloading
- Run Time Polymorphism: Method Overriding

Example of Compile Time Polymorphism
Method Overloading- Method with same name but with different arguments is called method overloading.
- Method Overloading forms compile-time polymorphism.
- Example of Method Overloading:
class A1
{
void hello()
{ Console.WriteLine(“Hello”); }

void hello(string s)
{ Console.WriteLine(“Hello {0}”,s); }
}


Example of Run Time Polymorphism
Method Overriding- Method overriding occurs when child class declares a method that has the same type arguments as a method declared by one of its superclass.
- Method overriding forms Run-time polymorphism.
- Note: By default functions are not virtual in C# and so you need to write “virtual” explicitly. While by default in Java each function are virtual.
- Example of Method Overriding:
Class parent
{
virtual void hello()
{ Console.WriteLine(“Hello from Parent”); }
}

Class child : parent
{
override void hello()
{ Console.WriteLine(“Hello from Child”); }
}

static void main()
{
parent objParent = new child();
objParent.hello();
}
//Output
Hello from Child.