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C# C# Basics (Retired) Perfect Final

Patrick Alcorta
Patrick Alcorta
4,056 Points

formatexception

I seem to be stuck here, I keep getting a value cannot be null error when trying out my code. Any suggestions?

Program.cs
using System;

namespace Treehouse.CodeChallenges
{
    class Program
    {
        static void Main()
        {
            var x = 0;           
            while (true)
            {
                            //Prompt user for how many yays they want
                            Console.Write("Enter the number of times to print \"Yay!\": ");
                            //Store the answer they put in the variable numberYays
                            var answer = Console.ReadLine();
                            var numberYays = 0;
                            try
                            {
                                //converting a string into a integer
                                numberYays = int.Parse(answer);
                            }  
                            catch(FormatException) 
                            {
                                Console.WriteLine("You must enter a whole number.");   
                                continue;
                            }

                            if(numberYays <= 0)
                            {
                                Console.WriteLine(numberYays + " is not an acceptable value.");
                                continue;
                             }


                             //this is the beginning of my while loop to restart asking how many yays they want.
                            while (numberYays > x)
                            {
                                Console.WriteLine("Yay!");
                                x ++;

                            }   
                break;
            }        
        }
    }
}

1 Answer

Steven Parker
Steven Parker
231,236 Points

:point_right: Your program "works", but deviates from the instructions.

This is a great example of how something that works (will compile an run) might not be what was asked for (satisfies the requirements). This has been a topic of many previous questions, but I'll repost the info here:

People often over-think this one and get too creative, and their answer is rejected for a variety of reasons (some which don't seem to make any sense).

Here are the secret "rules" you must follow for success on this one:

  • Your program must ask for and accept input ONE TIME ONLY
  • If the input validates, your program will perform exactly as in Task 1
  • If the input does not validate, it will print the error message and exit
  • Validation must be done by exception catching. There are other perfectly good methods that can be used for validation, but they will not pass this challenge

It looks like you have an extra loop that is violating the first and third "rule", and one of your error messages might not be what the challenge is expecting.