C#

BeingCache cache = BeingCache.CacheInstance;

Human ahuman = new Human("joe", "male");
Cat acat = new Cat("Meow", true);

IBeing b1 = cache[1]; // works

IBeing<Cat> b2 = (IBeing<Cat>) b1; // works

Cat cat = b2.IBInstance; // works

bool st0 = b2 is Cat; // false

bool st1 = b2 is Being<Cat>; // true

bool st2 = b2 is IBeing<Cat>; // true

Cat hepcat = BeingCache.GetBeing<Cat>(cache[1]); // works

IBeing<Cat> b3 = (IBeing<Cat>) cache[1]; // works

using System;
using System.Collections.Generic;

namespace InterfaceInheritance_2020
{
    public class Human
    {
        public Human(string name, string gender)
        {
            Name = name;
            Gender = gender;

            BeingCache.SetCache(this); //  :wtf: 
        }

        public string Gender{ get;}
        public string Name { get; }
    }

    public class Cat
    {
        public Cat(string name, bool haswhiskers = true)
        {
            Name = name;
            HasWhiskers = haswhiskers;

            BeingCache.SetCache(this); //  :wtf: 
        }

        public bool HasWhiskers { get; }
        public string Name { get; }
    }

    public interface IBeing
    {
        Type BeingType { set; get; }
    }

    public interface IBeing<T> : IBeing
    {
        T IBInstance { set; get; }
    }

    public class Being<T> : IBeing<T>
    {
        public Being(T content)
        {
            IBInstance = content;
            BeingType = typeof(IBeing<T>);
        }

        public Type BeingType { get; set; }
        public T IBInstance { get; set; }
    }

    //singleton 
    public sealed class BeingCache : List<IBeing>
    {
        private BeingCache()
        {
        }

        public static BeingCache CacheInstance{ get; } = new BeingCache();

        public static void SetCache<T>(T value)
        {
            CacheInstance.AddBeing(new Being<T>(value), typeof(T));
        }

        public void AddBeing(IBeing being, Type btype)
        {
            being.BeingType = btype;
            CacheInstance.Add(being);
        }

        public static T GetBeing<T>(IBeing being)
        {
            return (T) ((IBeing<T>) being).IBInstance;
        }
    }
}

private void textBoxTT_KeyPress(object sender, KeyPressEventArgs e)
       {
           if (!char.IsDigit(e.KeyChar))
               e.Handled = true;
           return;
       }

At the moment the program will only reveal a letter if the users input matches the specified letter within the iteration.

What I would like to do is reveal a letter despite what iteration the user is on...e.g. if the user inputs "P" on the first iteration I want the program to reveal all the Ps" in happy.

Thanks!

{
           
            string[] secret = { "h", "a", "p", "p", "y" };
            string[] hidden = { "_", "_", "_", "_", "_" };
            string letter = "";

            Console.WriteLine("Welcome to guess a word game");

            for (int i = 0; i < secret.Length; i++)
            {            
                Console.WriteLine("Guess a letter: ");
                letter = Console.ReadLine();

                //revealing letters
                if (secret[i]  == letter)
                {
                    hidden[i] = letter;
                }
                //displaying the word to the user after each guess
                foreach (string k in hidden)
                {
                    Console.Write(k.ToString());                  
                }
                Console.WriteLine();
            }
            Console.WriteLine();
         
            // once broken out of the for loop it will inform the user if they have guessed the word correctly.
            if(secret == hidden)
            {
                Console.WriteLine("You have guessed the correct word!");
            }
            else
            {
                Console.WriteLine("unfortunately you have not gussed the correct word");
            }
            Console.ReadLine();
        }
    }
}