Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

C# C# Basics (Retired) Perfect Final

Bummer! System.ArgumentNullException: Value cannot be null. Parameter name: String. See output for stack trace.

works fine in compiler. what have i missed?

Program.cs
using System;

namespace Treehouse.CodeChallenges
{
    class Program
    {
        static void Main()
        {
            Console.Write("Enter the number of times to print \"Yay!\": ");
            int N=0;

            while(true)
            {
            try
            {
                var entry = Console.ReadLine();
                N =  int.Parse(entry);

                break;
            }
            catch(FormatException)
            {
                Console.WriteLine("You must enter a whole number.");
                continue;
            }
            }
              while(N>0)
                {
                    Console.WriteLine("Yay!");
                    N--;
                }

        }
    }
}

1 Answer

Steven Parker
Steven Parker
231,236 Points

:warning: Be careful about testing a challenge in an external REPL or IDE.

If you have misunderstood the challenge, it's also very likely that you will misinterpret the results.

In this case, you have added an extra loop that prevents the program from ending..

A program that follows the challenge instructions will only ask for input one time, and either print "Yay!"s or an error message. But either way it should end.

Thanks, i removed the while(true) loop containing the try/catch and the code worked fine.