Is VB really case insensitive?

Question

I\'m not trying to start an argument here, but for whatever reason, it\'s typically stated that Visual Basic is case insensitive and C languages aren\'t (and somehow that is

Answer 1

The difference between VBA and VB.NET is just because VB.NET compiles continuously in the background. You'll get an error when you compile the VBA.

Like Jonathan says, when programming you can think of VB.NET as case-insensitive apart from string-comparisons, XML, and a few other situations...

I think you're interested in what's under the hood. Well, the .NET Common Language Runtime is case-sensitive, and VB.NET code relies on the runtime, so you can see it must be case-sensitive at runtime, e.g. when it's looking up variables and methods.

The VB.NET compiler and editor let you ignore that - because they correct the case in your code.

If you play around with dynamic features or late-binding (Option Strict Off) you can prove that the underlying run-time is case-sensitive. Another way to see that is to realise that case-sensitive languages like C# use the same runtime, so the runtime obviously supports case-sensitivity.

EDIT If you want to take the IDE out of the equation, you can always compile from the command-line. Edit your code in Notepad so it has ss and SS and see what the compiler does.

EDIT Quote from Jeffrey Richter in the .NET Framework Design Guidelines page 45.

To be clear, the CLR is actually case-sensitive. Some programming languages, like Visual Basic, are case insensitive. When the Visual Basic compiler is trying to resolve a method call to a type defined in a case-sensitive language like C#, the compiler (not the CLR) figures out the actual case of the method's name and embeds it in metadata. The CLR knows nothing about this. Now if you are using reflection to bind to a method, the reflection APIs do offer the ability to do case-insensitive lookups. This is the extent to which the CLR offers case-insensitivity.