Automatic properties compiler error

Question

Writing a simple class in c# comes up with error "Not all code path return a value"

public class Genre
{
    private string _name;

    public string Name
    {
        get => _name;
        set => _name = value;
    }
}

Which line? (compiles fine for me) This error is usually generated when a non-void function misses a return statement — Vladi Pavelka, Jul 11 '18 at 15:21
Compiles without error for me in LINQPad, with a `new Genre().Name = "hi";` thrown in for good measure. What's the actual failing code? — Jeroen Mostert, Jul 11 '18 at 15:21
In a side note, you can use the snippet propfull so you can write code faster and without errors - https://msdn.microsoft.com/en-us/library/z41h7fat.aspx — Afonso, Jul 11 '18 at 15:23
This is a new-ish syntax, so check which version of the C# compiler you're using. You'll need C# 6.0 or above, I think. Note that this is not the same as the .NET framework version. See https://davefancher.com/2014/08/25/c-6-0-expression-bodied-members/ and other online resources — ADyson, Jul 11 '18 at 15:24
see https://stackoverflow.com/a/49647107/5947043 (and many others again, if you take the time to google something like "check c# compiler version"). Google is your friend... — ADyson, Jul 11 '18 at 15:27
@ADyson I think it's C# 7, which means you must have VS 2017 or above. AnKing, what's your VS version? https://learn.microsoft.com/en-us/dotnet/csharp/whats-new/csharp-7#more-expression-bodied-members — Magnetron, Jul 11 '18 at 15:28
@AnKing: Open project in visual studio right click on project -> properties->build-> advance and check the language version dropdown... see what c# versions it show — huMpty duMpty, Jul 11 '18 at 15:28
I use VS2015, changed compiler version to 6, but still doesnt work. do I really need VS2017 for this syntax to work? — AnKing, Jul 11 '18 at 15:29
@AnKing As I said, you must have VS2017, otherwise you'll have to use the old way — Magnetron, Jul 11 '18 at 15:30
@Magnetron Good spot. It's C#6 for property "get" using this syntax, and C# 7 to use property "set" this way. See https://learn.microsoft.com/en-us/dotnet/csharp/programming-guide/statements-expressions-operators/expression-bodied-members for that. But also see https://stackoverflow.com/questions/39461407/how-to-use-c7-with-visual-studio-2015 - you can install different compilers into a particular project when using Nuget on VS 2015 and possibly earlier, although it's not clear if this is really supported or not. Of course a command-line compiler could always be used, instead. — ADyson, Jul 11 '18 at 15:31
@ADyson good to know. But as the post says, it'll work but will show sintax error. — Magnetron, Jul 11 '18 at 15:34
Might seem ridicolous, but make sure that you are compiling the right project. — Axel2D, Jul 11 '18 at 15:37
I think I'll just have to upgrade the visual studio at this point — AnKing, Jul 11 '18 at 15:38

score 2 · Accepted Answer · edited Jul 11 '18 at 17:52

2

This syntax is a new addition to C#7, so the options are:

Use Visual Studio 2017 or above, or VS Code (if dotnet core project)
Install the new compiler from Nuget, check this answer on how to do so

Use the old way:

public class Genre
{
    private string _name;

    public string Name
    {
        get { return _name; }
        set { _name = value; }
    }
}

edited Jul 11 '18 at 17:52

Hardik

3,038
2
19
31

answered Jul 11 '18 at 15:49

Magnetron

7,495
1
25
41

Automatic properties compiler error

1 Answers1