Question

I am writing a console application in C#. It is a receipt where the user inputs the item then quantity and then price per item. It is then validated through regular expressions. I need to put this in a multidimensional array to print out (command line print), like each row would have a columns for item, quantity, price and then subtotal for each item, but cannot figure it out. I also need the regular expression in a do while loop so when zero is entered alone it would end the user input but i am not sure if i should put that in the regular expression for item?? and start the array print out of the user input "receipt" with totals and then a final calculation of all subtotals added together with tax and total. i have this so far:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Text.RegularExpressions;

namespace Exam4
{
    class Program
    {
        static void Main(string[] args)
        {
            do
            {
                Regex reciept = new Regex(@"[a-zA-Z0-9 \(\)\&\+\-\.\_ ");
                string itemName;

                Console.WriteLine("Please Enter Item:");
                itemName = Console.ReadLine();

                while (reciept.Match(itemName).Success == false)
                {
                    Console.WriteLine("Invalid Entry");
                    Console.WriteLine("Enter Item: ");
                    itemName = Console.ReadLine();
                }
                if (reciept.Match(itemName).Success == true)
                {
                    Regex quant = new Regex(@"^[0-9]$");
                    string quantity;
                    Console.WriteLine("Please Enter Quantity: ");
                    quantity = Console.ReadLine();

                    while (quant.Match(quantity).Success == false)
                    {
                        Console.WriteLine("Invalid Entry");
                        Console.WriteLine("Enter Quantity");
                        quantity = Console.ReadLine();
                    }
                    if (reciept.Match(quantity).Success == true) ;
                    {
                        Regex price = new Regex(@"^[0-9\.]$");
                        string itemPrice;
                        Console.WriteLine("Enter Price");
                        itemPrice = Console.ReadLine();

                        while (price.Match(itemPrice).Success == false)
                        {
                            Console.WriteLine("Invalid Entry (only digits and . allowed");
                            Console.WriteLine("Enter Price: ");
                            itemPrice = Console.ReadLine();
                        }

                    }
                }
            }
            while ( != 0);

        }
    }
}

Answer 1

using System;
using System.Text.RegularExpressions;
                  
public class Program
{
   public static void Main()
   {
       string itemName;
            do
            {
                Regex reciept = new Regex(@"[a-zA-Z0-9] \\(\\)\\&\\+\\-\\.\\_ ");
              

                Console.WriteLine("Please Enter Item:");
                itemName = Console.ReadLine();

                while (reciept.Match(itemName).Success == false)
                {
                    Console.WriteLine("Invalid Entry");
                    Console.WriteLine("Enter Item: ");
                    itemName = Console.ReadLine();
                }
                if (reciept.Match(itemName).Success == true)
                {
                    Regex quant = new Regex(@"^[0-9]$");
                    string quantity;
                    Console.WriteLine("Please Enter Quantity: ");
                    quantity = Console.ReadLine();

                    while (quant.Match(quantity).Success == false)
                    {
                        Console.WriteLine("Invalid Entry");
                        Console.WriteLine("Enter Quantity");
                        quantity = Console.ReadLine();
                    }
                    if (reciept.Match(quantity).Success == true) ;
                    {
                        Regex price = new Regex(@"^[0-9\.]$");
                        string itemPrice;
                        Console.WriteLine("Enter Price");
                        itemPrice = Console.ReadLine();

                        while (price.Match(itemPrice).Success == false)
                        {
                            Console.WriteLine("Invalid Entry (only digits and . allowed");
                            Console.WriteLine("Enter Price: ");
                            itemPrice = Console.ReadLine();
                        }

                    }
                }
            }
            while (itemName!="0");

   }
}