Main: not all code paths return a value

Question

I am making list and want to look at it in console. I have one error, It says:

Main(): not all code paths return a value.

Maybe you could help me? Here is my code:

namespace ConsoleApplication5
{
    public class DocConfig
    {
        public string Description { get; set; }
        public List<DocPart> Parts { get; set; }

        public class DocPart
        {
            public string Title { get; set; }
            public string TexLine { get; set; }

            public class Program
            {
                public static int Main()
                {
                    List<DocPart> Parts = new List<DocPart>();
                    var doc = new DocConfig();
                    doc.Description = "bla bla";
                    doc.Parts = new List<DocPart>();
                    doc.Parts.Add(new DocPart { Title = "aaa", TexLine = @"\include{aaa.tex}" });
                    doc.Parts.Add(new DocPart { Title = "bbb", TexLine = @"\include{bbb.tex}" });
                    foreach (DocPart part in doc.Parts)
                    {
                        Console.WriteLine(part.Title);
                        {
                            Console.ReadLine();
                            return 0;
                        }
                    }
                }
            }
        }
    }
}

If your doc.Parts is empty,you will miss your return 0.Add anything in the last line of the method code — Suren Srapyan, Nov 13 '15 at 09:48
Off-topic but is there a reason you need nested classes? ... it looks like it is already getting messy — Sayse, Nov 13 '15 at 09:49
@Mantas: You *need* them to be nested classes? That sounds unlikely... — Jon Skeet, Nov 13 '15 at 09:51
If the method signature says it will return something, it has to do it in all conditions. If your list is empty, method will not return anything. So, you might return a default value at the end of the method, which will fix the compile error. Also, notice that, you are returning in a loop. So, in the first iteration itself the method will return, and the rest of the loop will not be executed. — Arghya C, Nov 13 '15 at 09:57
Possible duplicate of [c# returning error "not all code paths return a value"](http://stackoverflow.com/questions/21197410/c-sharp-returning-error-not-all-code-paths-return-a-value) — Liam, Jun 14 '16 at 10:01

score 3 · Accepted Answer · answered Nov 13 '15 at 09:47

3

Return something at the end of Main. Like this:

public static int Main()
{
     List<DocPart> Parts = new List<DocPart>();
     var doc = new DocConfig();
     doc.Description = "bla bla";
     doc.Parts = new List<DocPart>();
     doc.Parts.Add(new DocPart { Title = "aaa", TexLine = @"\include{aaa.tex}" });
     doc.Parts.Add(new DocPart { Title = "bbb", TexLine = @"\include{bbb.tex}" });
     foreach (DocPart part in doc.Parts)
     {
           Console.WriteLine(part.Title);
           {
                 Console.ReadLine();
                 return 0;
           }
     }

     return -1;
}

answered Nov 13 '15 at 09:47

Salah Akbari

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It says now, that return is class,struct or interface member declaration. Invalid token – Mantas Nov 13 '15 at 09:52
@Mantas ... It is because closing curly braces. Check where are you placed ` return -1;` – Salah Akbari Nov 13 '15 at 09:54
@Mantas...Make sure that you have placed ` return -1;` just before the end of the `Main` method. Also check you don't have extra closing curly braces. – Salah Akbari Nov 13 '15 at 09:58
Thank you!!! but still it show 1more error in line 12 invalid token " but there is empty row. what is this? – Mantas Nov 13 '15 at 10:00
@Mantas...Rebuild your solution once also verify again for extra closing curly braces. – Salah Akbari Nov 13 '15 at 10:01

score 1 · Answer 2 · answered Nov 13 '15 at 09:58

The reason that you are getting this error is because when you declared the method

public static int Main()

you declared it would return an int value. However, you only return that value in a place which might never be run. For instance, it would never be run if the doc.Parts list were to be empty. So, you need to add code that makes sure the method always returns something.

Adding return -1; in the end of the method, for example, would make the error go away in this case.

score 0 · Answer 3 · answered Nov 13 '15 at 09:53

 public static int Main()
            {
                List<DocPart> Parts = new List<DocPart>();
                var doc = new DocConfig();
                doc.Description = "bla bla";
                doc.Parts = new List<DocPart>();
                doc.Parts.Add(new DocPart { Title = "aaa", TexLine = @"\include{aaa.tex}" });
                doc.Parts.Add(new DocPart { Title = "bbb", TexLine = @"\include{bbb.tex}" });
                foreach (DocPart part in doc.Parts)
                {
                    Console.WriteLine(part.Title);
                    {
                        Console.ReadLine();
                        return 0;
                    }
                }
                return 0;
            }

Add some explanation please. – Arghya C Nov 13 '15 at 09:58 — Arghya C, Nov 13 '15 at 09:58

Main: not all code paths return a value

3 Answers3

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