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 Variable Scope

Posted by Maxine Lewis
Maxine Lewis
2,043 Points

Challenge Task 1 of 1 Compiling the below code currently produces the error: "The name 'output' does not exist in the c

Challenge Task 1 of 1 Compiling the below code currently produces the error: "The name 'output' does not exist in the current context". This error is the result of improper variable scoping.

The output variable is declared twice: once within the if statement's curly braces and again within the else statement's curly braces. Remember, variables in C# can only be used within the curly braces that they are declared within. The last line of code in this program, Console.WriteLine(output);, is attempting to use a variable named output, which doesn't exist outside of the if/else statement's curly braces.

To fix this error:

Declare the output variable just before the if statement and assign it to an empty string (i.e. ""). Remove the string data types from the output variables within the if/else statement's curly braces.

Program.cs 
using System;

namespace Treehouse.CodeChallenges
{
    class Program
    {
        static void Main()
        {            
            string input = Console.ReadLine();
            string output = Console.WriteLine();
            if (input == "quit")
            {
                string output = 
            }
            else
            {
                string output = 
            }

            Console.WriteLine(output);
        }
    }
}

5 Answers

Steven Parker
Steven Parker
231,210 Points
Steven Parker
Steven Parker
231,210 Points

You have the right idea, but there's still a few issues:

  • when you declare "output", you don't need to assign it with anything
  • you described it, but still need to remove the "string" declarations from the assignments
  • the rest of the assignments should remain as-is (don't remove the right-side expressions)
Maxine Lewis
Maxine Lewis
2,043 Points

Thanks so much for your help.

Tawanda Parayangiwa
Tawanda Parayangiwa
2,614 Points

MR PARKER in facing problems on this one too

Steven Parker
Steven Parker
231,210 Points
Steven Parker
Steven Parker
231,210 Points

Tawanda Parayangiwa — Start a new question, preferably using the "Get Help"button which will link to the page and paste in your code for you. Then, describe the issue you are having.

Steven Parker
Steven Parker
231,210 Points
Steven Parker
Steven Parker
231,210 Points

Why the downvotes?

Would any of the people who downvoted this answer please leave a comment about what was wrong with it? And any suggestions about how it can be improved.

Gancho Iliev
Gancho Iliev
10,264 Points
Gancho Iliev
Gancho Iliev
10,264 Points

Steven Parker, gives you a good hits. It's a bit tricky this on, just don't overthink it. This is what worked for me:

using System;

namespace Treehouse.CodeChallenges
{
    class Program
    {
        static void Main()
        {            
            string input = Console.ReadLine();
            string output = "";

            if (input == "quit")
            {
                 output = "Goodbye.";
            }
            else
            {
                 output = "You entered " + input + ".";
            }

            Console.WriteLine(output);
        }
    }
}
Welcome Julius
Welcome Julius
9,076 Points

anyone to help with codes

Paison Tazvivinga
Paison Tazvivinga
665 Points
Paison Tazvivinga
Paison Tazvivinga
665 Points

May you assist am failing to get past it also.

Steven Parker
Steven Parker
231,210 Points
Steven Parker
Steven Parker
231,210 Points

I would make the same suggestion to you that I made to Tawanda. A new question that shows your code will make it easier to get help.

Ignatious Mugwagwa
Ignatious Mugwagwa
2,556 Points
Ignatious Mugwagwa
Ignatious Mugwagwa
2,556 Points

this is how i solved the problem using System;

namespace Treehouse.CodeChallenges { class Program { static void Main() {
string output ="";

        string input = Console.ReadLine();
        string output = Console.WriteLine();
        if (input == "quit")
        {
          output 
        }
        else
        {
          output 
        }

        Console.WriteLine(output);
    }
}

}

Chelsea Mofiz
Chelsea Mofiz
15,153 Points
Chelsea Mofiz
Chelsea Mofiz
15,153 Points

using System;

namespace Treehouse.CodeChallenges { class Program { static void Main() {
string input = Console.ReadLine(); string output = ""; 

        if (input == "quit")
        {
             output = "Goodbye.";
        }
        else
        {
            output = "You entered " + input + ".";
        }

        Console.WriteLine(output);
    }
}

}