GenericsTests.cs

using System;

namespace GenericsTests1
{
    class Program
    {        
        static void Main(string[] args)
        {
            ExampleClass example = new ExampleClass();
            example.RunAll();
            
            Console.ReadKey();
        }
    }

    public class ExampleClass
    {
        string s = "Score";
        string result = "";

        string[] names = new string[5] { "Score 1", "Score 2", "Score 3", "Score 4", "Score 5" };
        string[] results = new string[5];
        int[] integers = new int[5] { 2, 4, 5, 1, 3 };
        double[] doubles = new double[5] { 2.3, 4.5, 5.4, 1.3, 3.1 };

        public void RunAll()
        {           
            AddIntScore_Test();
            AddIntScore_Extension_Test();

            AddGenericScore_Test();
            AddGenericScore_Test2();

            AddGenericScore_Func_Test();
            AddGenericScore_Func_Test2();

            AddGenericScore_LambdaFunc_Test();
        }

        public void AddIntScore_Test()
        {
            Console.WriteLine("AddIntScore_Test");

            result = Utilities.AddIntScore(s, 5);

            Console.WriteLine(result);
            Console.WriteLine();
        }

        public void AddIntScore_Extension_Test()
        {
            Console.WriteLine("AddIntScore_Test");

            result = s.AddIntScore_Extension(5);

            Console.WriteLine(result);
            Console.WriteLine();
        }

        public void AddGenericScore_Test()
        {
            Console.WriteLine("AddIntScore_Test");

            result = s.AddGenericScore(5);
            Console.WriteLine(result);
            Console.WriteLine();
        }

        public void AddGenericScore_Test2()
        {
            Console.WriteLine("AddGenericScore_Test2");

            result = s.AddGenericScore(5.6);
            Console.WriteLine(result);

            Console.WriteLine();
        }

        public void AddGenericScore_Func_Test()
        {
            Console.WriteLine("AddGenericScore_Func_Test");

            results = names.AddGenericScore(AddFunc);
            foreach (var item in results)
            {
                Console.WriteLine(item);
            }
            Console.WriteLine();
        }

        public void AddGenericScore_Func_Test2()
        {
            Console.WriteLine("AddGenericScore_Func_Test2");

            results = doubles.AddGenericScore(AddFunc2);
            foreach (var item in results)
            {
                Console.WriteLine(item);
            }
            Console.WriteLine();
        }

        public void AddGenericScore_LambdaFunc_Test()
        {
            Console.WriteLine("AddGenericScore_LambdaFunc_Test");

            results = names.AddGenericScore((x, i) => x + ": " + integers[i]);
            foreach (var item in results)
            {
                Console.WriteLine(item);
            }
            Console.WriteLine();
        }


        string AddFunc(string str, int i)
        {
            return str + ": " + integers[i].ToString();
        }

        string AddFunc2(double num, int i)
        {
            return (num * integers[i]).ToString();
        }
    }

    public static class Utilities
    {
        public static string AddIntScore(string str, int parameter)
        {
            return str + ": " + parameter.ToString();       
        }

        public static string AddIntScore_Extension(this string str, int parameter)
        {
            return str + ": " + parameter.ToString();
        }

        public static string AddGenericScore<T>(this string str, T parameter)
        {
            return str + ": " + parameter.ToString();
        }        

        public static TResult[] AddGenericScore<TInput, TResult>(this TInput[] input, Func<TInput, int, TResult> func)
        {
            TResult[] result = new TResult[input.Length];
            for (int i = 0; i < input.Length; i++)
                result[i] = func(input[i], i);
            return result;
        }

        public static TResult[] Apply<TInput, TResult>(this TInput[] vector, Func<TInput, int, TResult> func)
        {
            TResult[] result = new TResult[vector.Length];

            for (int i = 0; i < vector.Length; i++)
                result[i] = func(vector[i], i);
            return result;
        }

    }


}