C#_OOP_Features_DelegateTest

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace App1b
{
    // Declare delegate -- defines required signature:
    delegate double MathAction(double num);

    delegate void MyDelgate(string message);

    class DelegateTest
    {
        // Regular method that matches signature:
        double Double(double input)
        {
            return input * 2;
        }

        static public void Test()
        {
            // 1) Named Method
            DelegateTest p = new DelegateTest();
            MathAction d1 = p.Double;
            // MathAction d1 = new MathAction(Double);
            Console.WriteLine("The delagate says {0}", d1(3.14));

            // 2) Anonymous function
            d1 = delegate(double input)
            {
                return input * input;
            };
            Console.WriteLine("The delagate says {0}", d1(3.14));

            // 3) Lambda
            d1 = s => s * s * s;
            Console.WriteLine("The delagate says {0}", d1(3.14));

            // functional
            Console.WriteLine("Functional = {0}", p.Calculate(d1, 2.71));
        }

        public double Calculate(MathAction action, double param)
        {
            return action(param);
        }
    }
}