using System;

using System.Collections;

using System.Collections.Generic;

using System.Diagnostics;

​

public class Program

{

    #region Constansts and Statics

    public const int Repetitions = 1000000;

    public const string Part1 = "Part 1";

    public const string Part2 = "Part 2";

    public const string Part3 = "Part 3";

    public static Stopwatch Watch = new Stopwatch();    

    #endregion

    #region Main Program

    public static void Main()

    {

        Console.WriteLine("The purpose of this test is to see which string medho\n");

        var vPart1 = GetPartBy(1);

        var vPart2 = GetPartBy(2);

        var vPart3 = GetPartBy(3);

        TestStringsBy("const string interpolation ", () => $"{Part1}{Part2}{Part3}");

        TestStringsBy("const string concatenation ", () => string.Concat(Part1, Part2, Part3));

        TestStringsBy("const string addition      ", () => Part1 + Part2 + Part3);

        TestStringsBy("var string interpolation   ", () => $"{vPart1}{vPart2}{vPart3}");

        TestStringsBy("var string concatenation   ", () => string.Concat(vPart1, vPart2, vPart3));

        TestStringsBy("var string addition        ", () => vPart1 + vPart2 + vPart3);

        TestStringsBy("mixed string interpolation ", () => $"{vPart1}{Part2}{Part3}");

        TestStringsBy("mixed string concatenation ", () => string.Concat(vPart1, Part2, Part3));

        TestStringsBy("mixed string addition      ", () => vPart1 + Part2 + Part3);

    }

    #endregion

    #region Test

    private static void TestStringsBy(string info, Func<string> action)

    {

        var watch = Stopwatch.StartNew();

        for (var i = 0; i < Repetitions; i++)

        {

            action();

        }

​

        watch.Stop();

        Console.WriteLine($"{info}: {watch.ElapsedMilliseconds}");

    }

    #endregion

    #region Helper

    private static string GetPartBy(int index) => $"Part{index}";

    #endregion

}