only 4 integers allowed?

Question

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 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?

Alan · Answer

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(

The 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) != '') // 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 } while(sb.Length return sb.ToString(); } }