only 4 integers allowed?

Hi,
here the question.. i wanted to knw if i can set the limit of the input that user can keyin only 4 integers number.. by default, i use this kind of code ..
input:
                Console.WriteLine("4 integers number");
            Console.Write(" User input: ");
            int j = int.Parse(Console.ReadLine());
            if ((j < 1000) || (j > 10000))
            {
                Console.Clear();
                Console.WriteLine("Error!!Please input 4 digit integers");
                goto input;
            }

by the way, if u see the code.. 0000-0999 cant be read since the condition is 1000-10000..
so is there anyway to solve this problem so that i can input 0000-0999?

Yes, it's possible to restrict input to exactly 4 digits (including leading zeros) using code like the following:

using System;
using System.Text;

class Sample
{
    static void Main()
    {
        Console.Clear();
        Console.Write("Enter 4 digit Id : ");
        string idString = GetFourDigitInteger();
        int id = int.Parse(idString);
        Console.WriteLine("\n\nThe Id entered was {0}", id);
        Console.ReadKey();
    }

    public static string GetFourDigitInteger()
    {
        StringBuilder sb = new StringBuilder();
        char key;
        // only permit exactly 4 digits
        do
        {
           while ((key = Console.ReadKey(true).KeyChar) != '\r') // return
           {
              if (key == '\b' && sb.Length > 0) // backspace
              {
                 Console.Write(key + " " + key);
                 sb = sb.Remove(sb.Length - 1, 1);
              }
              else if (sb.Length == 4) / / 4 digits imput already
              {
                 Console.Beep();
              }
              else if (Char.IsDigit(key)) // otherwise any digit is OK
              {
                 Console.Write(key);
                 sb = sb.Append(key);
              }
           }
           if (sb.Length < 4) Console.Beep(); // can't exit until 4 digits input
        }
        while(sb.Length < 4);
        return sb.ToString();
    }
}

1 Reply

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Alan19y ago
Yes, it's possible to restrict input to exactly 4 digits (including leading zeros) using code like the following:

using System;
using System.Text;

class Sample
{
    static void Main()
    {
        Console.Clear();
        Console.Write("Enter 4 digit Id : ");
        string idString = GetFourDigitInteger();
        int id = int.Parse(idString);
        Console.WriteLine("\n\nThe Id entered was {0}", id);
        Console.ReadKey();
    }

    public static string GetFourDigitInteger()
    {
        StringBuilder sb = new StringBuilder();
        char key;
        // only permit exactly 4 digits
        do
        {
           while ((key = Console.ReadKey(true).KeyChar) != '\r') // return
           {
              if (key == '\b' && sb.Length > 0) // backspace
              {
                 Console.Write(key + " " + key);
                 sb = sb.Remove(sb.Length - 1, 1);
              }
              else if (sb.Length == 4) / / 4 digits imput already
              {
                 Console.Beep();
              }
              else if (Char.IsDigit(key)) // otherwise any digit is OK
              {
                 Console.Write(key);
                 sb = sb.Append(key);
              }
           }
           if (sb.Length < 4) Console.Beep(); // can't exit until 4 digits input
        }
        while(sb.Length < 4);
        return sb.ToString();
    }
}