Why does making this getter nullable cause a compile error?

Question

This code works:

class Example
{
    public Int32 Int32
    {
        get { return Int32.Parse("3"); }
    }
}

This code does not compile:

class Example
{
    public Int32? Int32
    {
        get { return Int32.Parse("3"); }
    }
}

CS1061 'int?' does not contain a definition for 'Parse' and no extension method 'Parse' accepting a first argument of type 'int?' could be found (are you missing a using directive or an assembly reference?)

---

My example may look silly, but it makes a lot more sense if you use imagine an enum, like

public Choice? Choice { get { return Choice.One; } }

Answer 1

In second example Int32 refers to property Int32 not to type System.Int32. And since the property Int32 is of type System.Nullable(System.Int32), it doesn't have a parse method.

You'll have to write,

public Int32? Int32
{
    get { return System.Int32.Parse("3"); }
}