public string AddItemToPool(string[] args) { if (args[0] != "FirePotion" && args[0] != "HealthPotion") { throw new ArgumentException($"Invalid item \"{args[0]}\"!"); } if (args[0] == "FirePotion") { Item item = new FirePotion(); items.Push(item); return($"{item.GetType().Name} added to pool."); } else { Item item = new HealthPotion(); items.Push(item); return($"{item.GetType().Name} added to pool."); } }