Why doesn't the C # Null Conditional operator return a Nullable <T>?

Question

I'm just wondering, "Why doesn't the NULL propagation operator (or can't) give any type information, such as returning null to type Nullable<int>?"

Since it returns nullwithout a type, the resulting value cannot pass the extension method.

class User {
     public string Name { get; set; }
     public User Father { get; set; }
}

var user = new User ( );


public static class Extensions {
    public static string X (this string p) => "EXTENSION METHOD";
}

C # interactive window:

> var user = new User();
> user.Father
null
> user.Father.Name
Object reference not set to an instance of an object.
> user.Father?.Name
null
> user.Father?.Name.X()
null

---

EDIT:

• Since @ScottChamberlain noted that it Nullable<string>is not compiled code. But I do not correct it. Since this question has already answered this question, and any body can easily solve the problem that I asked about.

Answer 1

, , .? null.

var result = user.Father?.Name.X()

string result;
var testObject = user.Father;
if(!Object.RefrenceEquals(testObject, null))
{
    result = testObject.Name.X();
}
else
{
    result = null;
}

Father , , .

, .? ,

var result = (user.Father?.Name).X()

string tempResult;
var testObject = user.Father;
if(!Object.RefrenceEquals(testObject, null))
{
    tempResult = testObject.Name;
}
else
{
    tempResult = null;
}
var result = tempResult.X();