How to tell whether a source code is written in Visual Basic or VB.Net?

I have never used Visual Basic before.

I have some source code for a project to look at. How can I tell whether the code has been written in VB or VB.Net?

Thanks.

I had a second look, it does not have any VB6 or VB.Net extension, but it has some ASP files, 1 CSS file and some .XLST extension files with HTML and what seems to be either VB or maybe VBScript i开发者_开发知识库nside.. I am not entirely sure whether it is VB or VBScript inside.

If the project file has the extension .VBP then it is VB6. If you have a .VBPROJ file then it is VB.NET

If you don't have a project file, then the best indicators are Import directives or object oriented programming keywords like Inherits or Implements

Files created from Visual Basic 6.0 will have a .bas extension. Files created from Visual Studio .NET and up will have a .vb extention. This isn't a perfect test, but it might get you close.

There's no definitive answer here because there is a large margin of compatibility between the languages. For example the following is legal in both VB.Net and VB6

Function Add(ByVal x, ByVal y)
  Add = x + y
End Function

That being said, any of the following wound be a strong indicator of VB.Net code

• Import directives
• SyncLock, Using statements
• Friend, Protected access modifier
• ByRef parameter modifier

And the following would be a strong indicator of VB6

• Global access modfifier

One thing you can look for is a <filename>.vbproj file. If you see that then you've got a Visual Studio VB.Net project. If the file is missing that doesn't necessarily mean its VB6 though.

If you see <filename>.frm files then you've got VB6 code.