c# compiler returning error not all code paths return a value

Question

get
{
    string dirName = System.IO.Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
    string pathName;
    DirectoryInfo d = new DirectoryInfo("TradeBotData");
    if (!d.Exists)
    {
        if (d.Parent.Name.ToString() == "Plugins")
        {
            d.Create();
            return d.FullName;
        }
    }
    else
    {
        if (d.Parent.Name.ToString() == "Plugins")
        {
            return d.FullName;
        }
        else
        { 
            Console.WriteLine("Data path Fallback!!!");
            pathName = System.IO.Path.Combine(dirName, @"\TradeBotData");
            System.IO.Directory.CreateDirectory(pathName);
            Console.WriteLine("Created Save Folder At: {0} :", pathName);
            return pathName;
        }
    }
}

I'm not really sure why this happens. I think that all code paths return a value because I have if and else. If I insert return ""; into the code it just returns ""; infinitely.

Please advise.

you have to return something when `if (d.Parent.Name.ToString() == "Plugins")` fails. — Hari Prasad, Jun 14 '16 at 08:13
To expand Hari's comment: In the case where the directory doesn't exist, so you're going into the body of the first `if` statment; if the parent name isn't `Plugins`, you then don't return anything. — Jon Skeet, Jun 14 '16 at 08:15

user3378165 · Accepted Answer · 2016-06-14T08:38:33.480

3

If your DirectoryInfo doesn't exist, the compiler will check if d.Parent.Name.ToString() == "Plugins" if it is, the code withing the if statement will be executed but otherwise the compiler will throw an exception: "not all code path return a value" because you don't return anything.

So you are missing a return here:

get
{
string dirName =System.IO.Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
    string pathName;
    DirectoryInfo d = new DirectoryInfo("TradeBotData");
    if (!d.Exists)
    {
        if (d.Parent.Name.ToString() == "Plugins")
        {
            d.Create();
            return d.FullName;
        }
     //////////HERE///////
    }
    else
    {
        if (d.Parent.Name.ToString() == "Plugins")
        {
            return d.FullName;
        }
        else
        { 
            Console.WriteLine("Data path Fallback!!!");
            pathName = System.IO.Path.Combine(dirName, @"\TradeBotData");
            System.IO.Directory.CreateDirectory(pathName);
            Console.WriteLine("Created Save Folder At: {0} :", pathName);
            return pathName;
        }
    }
}

edited Jun 14 '16 at 08:38

answered Jun 14 '16 at 08:17

user3378165

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What the op want to do, to solve this issue? – sujith karivelil Jun 14 '16 at 08:21
un-lucky I'm not sure what you mean.. – user3378165 Jun 14 '16 at 08:23
You have identified the issue, To make it a perfect answer you need to suggest solution for him – sujith karivelil Jun 14 '16 at 08:25
@user3378165 Along with providing solution, explain what is wrong how that can be fixed (some details). – Hari Prasad Jun 14 '16 at 08:25
Thank you for the great comments, you are totally right, I will edit my answer to include an explanation. Thank you! – user3378165 Jun 14 '16 at 08:26

score 0 · Answer 2 · answered Jun 14 '16 at 09:26

Initialize pathName to empty string. Then set it in your if/else logic and in the and of get just return it:

  get
            {
              string dirName = System.IO.Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
              string pathName = String.Empty;
              DirectoryInfo d = new DirectoryInfo("TradeBotData");
              if (!d.Exists) {
                if (d.Parent.Name == "Plugins") {
                  d.Create();
                  pathName = d.FullName;
                }
              } else {
                if (d.Parent.Name == "Plugins") {
                  pathName = d.FullName;
                } else {
                  Console.WriteLine("Data path Fallback!!!");
                  pathName = System.IO.Path.Combine(dirName, @"\TradeBotData");
                  System.IO.Directory.CreateDirectory(pathName);
                  Console.WriteLine("Created Save Folder At: {0} :", pathName);

                }
              }

              return pathName;
            }

c# compiler returning error not all code paths return a value

2 Answers2