C# While loop bryts ej,

namespace Menu
{
    class Program
    {
        static void Main()
        {
            string[] test = new string[5];
            MainMenu();
            int menuoption;
            Int32.TryParse(Console.ReadLine(), out menuoption);
            string userInput;

            while (menuoption <= 5)
            switch (menuoption)
            {
                case 1:
                    for (int i = 0; i < 5; i++)
                    {
                        Console.Write("Write the word you want add: ");
                        test[i] = Console.ReadLine();
                            menuoption++;
                    }
                   
                    break;
                case 2:
                    {
                 Console.WriteLine("Following words exists : \n\n{0} \n{1} \n{2} \n{3} \n{4} ", test[0], test[1], test[2], test[3], test[4]);
                    }
                    break;
                case 3:
                    {
                        Console.WriteLine("Write one word to add: ");
                        userInput = Console.ReadLine();
                        Console.WriteLine("Following word: " + userInput + " has been added");
                           
                    }
                    break;
                case 4:
                    Console.Write("Write the word you are searching for: ");

                    string sök = Console.ReadLine();
                    bool flag = false;
                    for (int i = 0; i < 5; i++)
                    {
                        if (test[i] == sök)
                        {
                            flag = true;
                        }
                    }
                    if (flag)
                    {
                        Console.WriteLine("Following word has been found:" + sök);
                    }
                    break;
                case 5:
                    Console.WriteLine("Press 'Enter' to exit' ");
                    Console.ReadLine();
                    Environment.Exit(0);
                  
                    break;

                default: // 
                    Console.Write("\nWrong input, please try again");
                    break;
            }
            MainMenu();
        }

        private static bool MainMenu()
        {
            Console.WriteLine("\n\n[1]Add five words to the list");
            Console.WriteLine("[2] View all words");
            Console.WriteLine("[3] Add one word ");
            Console.WriteLine("[4] Search ");
            Console.WriteLine("[5] Quit");
            Console.Write("\nChoose:");
           return true;
        }

    }
}

while (menuoption <= 
switch (menuoption)

while (menuoption <= 4) 
{
  switch() 
  {
    ...
  }
  ...
  MainMenu();
}