Why remove unused using directives in C#?

Question

I\'m wondering if there are any reasons (apart from tidying up source code) why developers use the \"Remove Unused Usings\" feature in Visual Studio 2008?

Answer 1

There are a few reasons you'd want to take them out.

• It's pointless. They add no value.
• It's confusing. What is being used from that namespace?
• If you don't, then you'll gradually accumulate pointless using statements as your code changes over time.
• Static analysis is slower.
• Code compilation is slower.

On the other hand, there aren't many reasons to leave them in. I suppose you save yourself the effort of having to delete them. But if you're that lazy, you've got bigger problems!