Polymorphism

When a message can be processed in different ways is called polymorphism.

Polymorphism is of two types:

· Overloading: In method overloading method performs the different task at

the different input parameters with same method name and in same class.

· Overriding: Overriding a method is to change the behavior of the method for

the derived class. Overriding is done using inheritance and virtual functions.

Example

To explain the concept of overloading I have created two classes Poly and

abc(inherits poly).

//creating object of poly class
poly p= new poly();
    public class poly
    {
 //these two functions, sum(), are overloaded.
        public int sum(int x, int y)
        {
            return (x + y);
        }
        public virtual int sum(int x, int y, int z)
        {
            return (x + y + z);
        }
    }
 
    public class abc : poly
    {
 //overriding function sum(), of base class poly
        public override int sum(int x, int y, int z)
        {
            return (x + y + z + 10);
        }
    }

private void btnTwo_Click(object sender, EventArgs e)
        {
            int a, b,sum;
            a= int.Parse(textBox1.Text);
            b= int.Parse(textBox2.Text);
 //calling sum(a,b) of poly
            sum= p.sum(a, b);
            MessageBox.Show("Sum of (Box 1 & 2): " + sum.ToString(), "Two parameters");
        }
 
        private void btnThree_Click(object sender, EventArgs e)
        {
            abc x1 = new abc();
            int a, b, c, sum,sum1,sum2;
            a = int.Parse(textBox1.Text);
            b= int.Parse(textBox2.Text);
            c= int.Parse(textBox3.Text);
            poly p = new poly();
 //calling sum(a,b,c) of poly
            sum1=p.sum(a,b, c);
 //calling override function sum()           
            p= new abc();
            sum2 = p.sum(a, b, c);
            MessageBox.Show("Sum of (Box 1, 2 & 3): " + sum1.ToString(), "Three Parameters");
            MessageBox.Show("Sum of (Box 1, 2 & 3): " + sum2.ToString(), "Three Parameters");
        }