How to handle nameof(this) to report class name

nincsmail picture nincsmail · Jan 8, 2015 · Viewed 10.4k times · Source

I'd like to use the following C#6 code

var joe = new Self();
Console.WriteLine(joe);

... and get the following output:

joe

The following attempt

class Self {
  public string Name { get; set; } = nameof(this);
  public override string ToString() {
    return Name;
  }
}

fails as nameof cannot be applied to this. Is it there a workaround for this problem?

EDIT. The scenario I'm working with assures that no two references point to the same Self object.

Answer

Jon Skeet picture Jon Skeet · Jan 8, 2015

No, nameof is designed to refer to the compile-time name of the member you're referring to. If you want an object to have a Name property as part of its state, that is independent of how you get to the Name property - as Frédéric Hamidi says, there could be multiple variables (or none) referring to the same object. Basically you need to differentiate between an object and a variable which happens to refer to that object.

However, if you have a constructor to specify the name, you could then use a couple of tricks to make it easier to get the right name:

class Self
{
    public string Name { get; }

    public Self([CallerMemberName] string name = null)
    {
        this.Name = name;
    }
}

Then:

class Foo
{
    private Self me = new Self(); // Equivalent to new Self("me")

    public void SomeMethod()
    {
        // Can't use the default here, as it would be "SomeMethod".
        // But we can use nameof...
        var joe = new Self(nameof(joe));
    }
}