It's pretty simple. Every time I delete a line, there are a handful fewer troublesome bytecodes in the world that can cause a bug, and that can surely only be a good thing. There are, of course, perils, but I'm all about high-octane thrills. I'm not talking about mere refactoring here - taking 3 lines of code and coming up with the sort of one-liner that über-geeks love to use for oneupmanship. I'm talking taking a good look at your code and thinking about what really matters. Is this code actually doing anything useful?
There are many reasons to be deleting code. Perhaps you found a better way of doing things and have refactored. Perhaps requirements have changed and some functionality is no longer needed. Perhaps you just went too far in the first place and made up a requirement in your head. Occasionally, you have the headbanging moment when the compiler forces you to add code against your will to deal with a situation that will never occur.
But, remember the rules:
- Delete, don't comment - Commenting out unused code is a bit like putting dog poo in a bag and then leaving the bag. If you're using version control (and if you're not, you're on your own), then all this history is freely available to you. With modern DVCS systems like git, it's a no-brainer to start a repo anywhere you like, and to search back through history if you ever want to dig out that code again.
- YAGNI - it's far too tempting to think "but this might come in handy one day...". If it's not being used now, get rid of it. Again, if you want it in the future, it's safe and warm in the repo. But not today.
- Delete mercilessly and thoroughly - Don't just remove the obvious chunk of code. Inevitably there will be tests that call that code, configuration parameters, text strings - all sorts of other cruft that will be rendered redundant when you delete that code. If it's not used right here, right now, delete it.
I'm going to stick my neck out and suggest that most codebases could probably lose 10% of bug-generating, coder-baffling, readability-stifling code, and still do exactly the same job. So, grab your Ctrl, grab your D, and get deleting. Watch your test coverage stats soar!