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C# C# Basics (Retired) Perfect Final

Simen Fossnes
Simen Fossnes
3,226 Points
Posted by Simen Fossnes
Simen Fossnes
3,226 Points

I get a System.ArgumentNullException on this when I shouldn't.

My code works. The only thing I canged that stopped it from working was adding a while loop in task 3. This created an error in task two, with no apparent change to the code I had in task 2 (a try catch statement with a FormatException).

Here is my code: using System;

namespace Treehouse.CodeChallenges { class Program { static void Main() {

      int yays = -1;  

      while (true)
      {
        // asks the user for input
        Console.Write("Enter the number of times to print \"Yay!\": ");

        // takes input, and checks if it's a number or not
        try 
        {
          yays = Int32.Parse(Console.ReadLine());
        }
        catch (FormatException e)
        {  
          Console.Write("You must enter a whole number.");
        }

        // checks for positive number
        if (yays >= 0)
        {
            break;
        }
        else
        {
            Console.Write("You must enter a positive number.");
        }
      } 

      var counter = 0;
      while (yays > counter) 
      {
        Console.WriteLine("Yay!");
        ++counter;
      }
    }
}

}

The error is traced to the Int32.Parse bit of the code. Very strange, as I seem to get it running with no problem in visual studio on my laptop.

Program.cs 
using System;

namespace Treehouse.CodeChallenges
{
    class Program
    {
        static void Main()
        {

          int yays = -1;  

          while (true)
          {
            // asks the user for input
            Console.Write("Enter the number of times to print \"Yay!\": ");

            // get input from the user
            string inputString = Console.ReadLine();

            // checks if it's a number or not
            try 
            {
              yays = Int32.Parse(inputString);
            }
            catch (FormatException e)
            {  
              Console.Write("You must enter a whole number.", e);
            }

            // checks for positive number
            if (yays >= 0)
            {
                break;
            }
            else
            {
                Console.Write("You must enter a positive number.");
            }
          } 

          // prints the amount of yay's to the console.
          var counter = 0;
          while (yays > counter) 
          {
            Console.WriteLine("Yay!");
            ++counter;
          }
        }
    }
}

1 Answer

Simen Fossnes
Simen Fossnes
3,226 Points
Simen Fossnes
Simen Fossnes
3,226 Points

Okey, think I found the answer. Looks like the program should be designed to fail if an exception is thrown; not continue. The code testing probably didn't work since the tests are assuming that the program should crash, and then ends up not doing that with a while loop. I also didn't have a way to exit the program, yet that shouldn't be a problem. A program like this would exit befor the user could comprehend all the yay's printed... which is not good UI.