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Answer 1

+7 A:

VB.Net has both strong and weak typed modes. It is controlled via the Strict option. This can be set at a project or source file level.

' Enable VB.Net strong typing 
Option Strict On

' Enable VB.Net weak / dynamic typing
Option Strict Off

JaredPar 2010-08-18 23:48:05

wow... thank you very much!!! Once I turn it on, over 1000 compilation errors. hahahaa~ Really thanks!!!

Alex Yeung 2010-08-18 23:59:23

One more question, do you know how to make a strong-typed `IIf`? In C#, the `?:` operator is strong-typed.

Alex Yeung 2010-08-19 00:06:42

If you're using Visual Studio 2008 use `If` instead of `IIf` IIRC

JaredPar 2010-08-19 00:09:41

You could also set Option Strict On at project level so all your code files have strong type. Go to the Compile page of your project's properties and set Option Strict over there.

Alex Essilfie 2010-08-19 09:05:34

@JaredPar: Wrong. VB.NET's `IIf` is better than VB6's. In VB6, both the true and false part of the `IIf` function are evaluated irrespective of the condition being true or false. In VB.NET the condition is evaluated first and depending on the result, the true Statement or false statement is executed. This is equivalent to C#'s `condition ? truePart : falsePart`. Unless you want us to also avoid using C#'s ternary operator, I see no reason we shouldn't use VB.NET's `IIf`.

Alex Essilfie 2010-08-19 09:09:56

@Alex Jared is right, actually. IIf acts like the vb6 version, and If is like ? in C#. Jared does work on the vb.net compiler, you know!

MarkJ 2010-08-19 12:34:32

@MarkJ: My bad. I thought he was referring to the `If(condition, truePart, falsePart)` function of VB.NET.

Alex Essilfie 2010-08-19 13:02:54

@Alex But I think Jared *was* referring to the `If(condition, truePart, falsePart)` operator in Vb.Net? `If` short-circuits, unlike `IIf`, and `If` also works better with type inference. See the docs http://msdn.microsoft.com/en-us/library/bb513985(v=VS.90).aspx

MarkJ 2010-08-19 13:15:54

@Alex, @MarkJ is correct that I was referring to the short-circuiting, type inference friendly `If` operator. But I don't work on the VB.Net compiler anymore although i do still participate in C# and VB.net design. I work on a language / OS research project now.

JaredPar 2010-08-19 15:41:13

Answer 2

A:

I recently hit the Option Strict button on an older vb.net project and spent several hours fixing type errors, but it was worth it. Be sure to be very carefull around DateTime to string, and string to DateTime conversions. I had several instances of "12:00:00 AM" tacked onto the end of textboxs that would cause issues with the old codebase.

Once the errors are clear you can turn Option Infer on so Dim will work like c#'s var, and you don't have to explicitly type all your Linq queries.

(I'd have made this a comment but it seems I need more points, sorry)

asawyer 2010-08-19 16:23:28

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VB.NET weak-typed? strong-typed?

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