Error CS0161 not all code paths return a value 1

[justhumm]

I'm playing around with a class library in Visual Studio, integrating ExcelDNA to make a (few) User Defined Function for Excel.

The only error I am receiving is for the top "public static string StrCase" statement, but I haven't been able to figure out what the problem is. What do I need to do to get rid of this error?...what am I missing?

Error CS0161 not all code paths return a value

...I'm completely new to C#, by the way. Thanks!

         public static string StrCase
            ( [ExcelArgument(Name="String",Description ="Text string that is to have letters' case change.")]
              string str,
              [ExcelArgument(Name ="Case",Description ="0 = no case change,
               1 = change to UPPERCASE, 2 = change to lowercase, 3 = Change To Title Case")]
               byte bCase = 0
            )
                { if (bCase <= 0 || bCase > 3)   // "||" is the C# OR operator
                    { return str;
                    }
                  else
                    { TextInfo strTI = new CultureInfo("en-US", false).TextInfo;
                      if (bCase != 1)
                        { return str.ToLower();
                        }
                      if (bCase != 2) // "!=" is the equivalence operator
                        { return str.ToUpper();
                        }
                      if (bCase != 3)
                        { str = strTI.ToTitleCase(str);
                          return str;
                        }
                    }
                }

 

[xwb]

Two problems.
1)

    if ...
    else
    {
        if ... return
        if ... return
        if ... return
        // Compiler complaining out what if none of the above conditions are satisfied.
    }

2) If bcase is 1, the bcase != 2 is satisfied
if bcase is 2, the bcase != 1 is satisfied
if bcase is 3, the bcase != 1 is satisfied

it never gets to bcase != 3.

It is better if you check for equality instead of inequality

 

[justhumm]

Thanks, xwb...

I'm an idiot. I was overly tired and misread C# documentation regarding equality comparison.

I corrected mistakes and compiled without a problem, but I was getting a weird error from Excel.

I tracked it down to one of the argument definitions and changed it from "byte" to "int" and then it ran okay. Any idea why Excel was rejecting the byte variable?

        [ExcelFunction(Description = "Changes the case of the letters in a text string.")]
        public static string ChangeCase
            ([ExcelArgument(Name="String",Description ="Text string that is to have the case of letters changed.")]
              string ChangeStr,
             [ExcelArgument(Name ="Case",Description ="0 = no case change, 1 = change to UPPERCASE, 2 = change to lowercase, 3 = Change To Title Case")]
              int bCase = 0
              // Byte bCase = 0
            )