Why does this code not throw an exception?

Question

I expected the following lines of code to throw an exception since I am accessing the Value property of a nullable variable that is assigned a value of null. However, I do not get any exception when I execute the below:

int? x=null;
Console.WriteLine(x.Value==null);

But when I do:

Console.WriteLine(x.Value);

I do get an exception, as could be expected.

But what is the difference between the 2 ways of accessing x.Value? Why do I not get an exception in the first case? Both pieces of code are after all trying to access the x.Value property.

Note: I am running the above pieces of code on the www.compileonline.com website, btw. Not sure if trying on the Visual Studio compiler would yield different results, but I do not have access to Visual Studio currently.

TIA.

Answer 1

When using the website compile online you point out, the mono compile does a rewrite/optimalization of your code:

using System.IO;
using System;

class Program
{
    static void Main()
    {
        int? x=null;
        Console.WriteLine(x.Value==null);  //-> Console.WriteLine(false);    
    }
}

---

Compiling the source code....

$mcs main.cs -out:demo.exe 2>&1

main.cs(9,38): warning CS0472: The result of comparing value type int' with null isfalse'

Compilation succeeded - 1 warning(s)

Executing the program....

$mono demo.exe

False

warning CS0472 tell you that, it is a bug in the online/mono compiler they are using.