Program.cs

using Mission3;

List<FoodItem> foodItems = new List<FoodItem>();

int choice = 0;
while (choice != 4)
{
    Console.WriteLine("Choose an option: 1. Add, 2. Delete Food Item, 3. Print food items. 4. Exit");
    
    // Add reprompt for not adding int. 
    string input = Console.ReadLine();
    bool isValid = int.TryParse(input, out choice);
    
    if (!isValid)
    {
        Console.WriteLine("Please enter a valid number. ");
        continue;
    }
    
    if (choice == 1)
    {
        Console.WriteLine("Enter food item name: ");
        string name = Console.ReadLine();
        Console.WriteLine("Enter food item category: ");
        string category = Console.ReadLine();
        Console.WriteLine("Enter quantity: ");
        int quantity = int.Parse(Console.ReadLine());
        if (quantity < 0) // Make sure that quantity is not negative.
        {
            Console.WriteLine("Quantity cannot be negative.");
            continue;
        }
        Console.WriteLine("Enter expiration date: ");
        DateTime expirationDate = DateTime.Parse(Console.ReadLine());
        FoodItem newItem = new FoodItem(name, category, quantity, expirationDate);
        foodItems.Add(newItem);
        Console.WriteLine();
    }
    if (choice == 2)
    {
        if (foodItems.Count == 0) // Error handling for no food items.
        {
            Console.WriteLine("No food items found.");
            continue;
        }
        for (int i = 0; i < foodItems.Count; i++)
        {
            Console.WriteLine((i + 1) + ": " +  foodItems[i].Name); // Add one to make show from 1 instead of from 0.
        }

        Console.WriteLine("Enter the number of the item to delete:");
        int index = int.Parse(Console.ReadLine()) - 1; // Subtract one to remove actual list entry for that number instead of number shown that they selected.
        if (index < 0 || index >= foodItems.Count) // Make sure that the number selected is actually a number of item.
        {
            Console.WriteLine("Invalid selection.");
            continue;
        }
        foodItems.RemoveAt(index);
        Console.WriteLine();
    }
    if (choice == 3)
    {
        Console.WriteLine();
        foreach (FoodItem item in foodItems)
        {
            Console.WriteLine(item.Name + " -  " + item.Category + " - " + item.Quantity +  " - " + item.ExpirationDate);
        }
        Console.WriteLine();
    }
}