using System;

​

public class Program

{

    // A normal method definition

    public static float Sum(int a, int b)

    {

        return a + b;

    }

​

    // A lambda method definition

    public static float Product(int a, int b) => a * b;

    // Declaration of a delegate type 

    public delegate int Calculate (int n1, int n2);

    // Create an instance of the delegate and assign an anonymous method to it the old/normal way

    static Calculate mathDel = delegate(int n1, int n2) {return n1 - n2;};

    // see the lambda version of this below, in the main

​

​

    /***** Drivers for the methods above *****/

    public static void Main()

    {

        Console.Write("Test Sum method: ");

        Console.WriteLine(Sum(5, 7));

        Console.Write("Test Product method: ");

        Console.WriteLine(Product(5, 7));

        Console.Write("Test mathDel with subtract method: ");

        Console.WriteLine(mathDel(5, 7));

        // assign a new method to mathDel using a lambda and test it

        mathDel = (nm1, nm2) => {return nm1 * nm2;};

        Console.Write("Test mathDel with multiply method: ");

        Console.WriteLine(mathDel(5, 7));

​

    }

​

}