I want only Integer Input...!

Question

hi em new in Csharp Language...!

i want take only Integer input or you can say any number...!

if user enter any character then it takes input again until they enter correct number....!

my code is:

int mynum;
String number;

Console.WriteLine("Please Enter the roll number");

number = Console.ReadLine();// this is used for take input as a string

mynum = int.Parse(number); // this is used for to convert String nto integer.

// i dont konow what is the next step for take only integer input

Ryan Alford · Answer

TryParse() will not throw an error. It will return a boolean value which represents whether the value was converted or not.

Maha · Answer

Simple solution for a problem is always better than the most complex one. I found Alan solution is most simple one. I tried int .TryParse() in the Microsoft Visual C# 2008 Express Edition environment when I entered something other than the integer it was not throwing an exception.

Ryan Alford · Answer

please avoid using GOTO statements.

Alan · Answer

It worked fine when I tried it just now. Here's my test program: using System; class Test { static void Main() { int mynum; String number; bool isInteger; do { Console.WriteLine(Please Enter the roll number); number = Console.ReadLine(); isInteger = int.TryParse(number out mynum); } while(!isInteger); Console.WriteLine(The number entered is {0} mynum); Console.ReadLine(); } } However if you're using NET 1.0 or 1.1 (Visual Studio 2002 or 2003) then there's no TryParse() method. Instead do this: using System; class Test { static void Main() { int mynum = -1; // need to set a default value here String number; bool isInteger; do { Console.WriteLine(Please Enter the roll number); number = Console.ReadLine(); isInteger = true; try { mynum = int.Parse(number); } catch { isInteger = false; } } while(!isInteger); Console.WriteLine(The number entered is {0} mynum); Console.ReadLine(); } }

Asad Mairaj · Answer

manish reply is good but em new in C sharp so i have no idea about gotostart; and alan code is not execute...!

Asad Mairaj · Answer

thankx man.....!

Alan · Answer

To ensure you only obtain integer input you should use int.TryParse() rather than int.Parse() because the latter will throw an exception if you enter something that isn't an integer: int mynum; String number; bool isInteger; do { Console.WriteLine(Please Enter the roll number); number = Console.ReadLine(); isInteger = int.TryParse(number out mynum); } while(!isInteger);

Manish Dwivedi · Answer

Hi Try this code: static void Main( string [] args) { start: Console .WriteLine( Please Enter the roll number ); string number = Console .ReadLine(); if ( Regex .IsMatch(number ^[0-9]{15}$ )) { Console .WriteLine( Your Input is: ); Console .WriteLine( ******************* ); Console .WriteLine(number); Console .WriteLine( ******************* ); } else goto start; } and don't forget to include using System.Text.RegularExpressions; Happy Coding!!