Can C# compiler compile a VB.Net code?

Question

I found following on a ASP.NET book. I am learning and curious about following content.

The second major advantage of an IL architecture is that it en

Answer 1

They have separate compilers (csc.exe for C# and vbc.exe for VB.Net) but they both get compiled into IL and then at run-time JIT compiles it into machine code.

Question 1 : can C# compiler compile VB.net code?

Answer 1: No it can't and you will see that in the below example. It gives an error if you try to do that as it looks for C# syntax.

Question 2: I think that's what they say in the book. Since it is two compilers, I feel it is not compatible

Answer 2: It doesn't say that you can compile VB code using C# but it says that you can mix languages in a single application like I did in the example below and still able to compile C# and VB (using their compilers).

See below example to understand how it works. I created a solution with a C# project with a C# class and a VB project with a VB class. You should not mix C# and VB classes in same project as it will ignore the vb file if its a C# project during build.

Content of ClassCSharp.cs:

namespace ClassLibraryCSharp
{
    public abstract class ClassCSharp
    {
        public int MyProperty { get; set; }

        protected abstract void Test();
    }
}

Content of ClassVBInCSharp.vb in C# ClassLibrary. See how I can inherit from a C# class and also access its properties and override the method.

Namespace ClassLibraryVB
    Public Class ClassVBInCSharp
        Inherits ClassCSharp
        Property Test2 As Integer

        Protected Overrides Sub Test()
            Test2 = MyBase.MyProperty
        End Sub
    End Class
End Namespace

See below commands I ran:

vbc.exe /reference:"ClassLibraryCSharp.dll" /target:library /out:"ClassLibraryCSharpVbVersion.dll" "ClassVBInCSharp.vb"
Microsoft (R) Visual Basic Compiler version 12.0.20806.33440
Copyright (c) Microsoft Corporation.  All rights reserved.

See above VB Compiler is used to compile vb class.

csc.exe /reference:"ClassLibraryCSharp.dll" /target:library /out:"ClassLibraryCSharpVersion.dll" "ClassVBInCSharp.vb"
Microsoft (R) Visual C# Compiler version 4.0.30319.33440 for Microsoft (R) .NET Framework 4.5
Copyright (C) Microsoft Corporation. All rights reserved.

ClassLibrary1\ClassVBInCSharp.vb(1,1): error CS
0116: A namespace cannot directly contain members such as fields or methods

See above if I try to use C# Compiler to compile vb class it throws an error as its looking for C# syntax.