> > 发自我的 iPad > > > 在 2014年7月28日，22:20，Andrea Faulds <a...@ajf.me (mailto:a...@ajf.me)> 写道： > > > > > > On 28 Jul 2014, at 15:00, Derick Rethans <der...@php.net > > (mailto:der...@php.net)> wrote: > > > > > > Well, we don’t need to allow all of C99. We can simply allow using > > > > features that are widely supported and actually useful. For example, > > > > declarations between statements, > > > > > > > > > > > > > I think that makes code a lot less readable, so I would not be in favour > > > allowing this in our coding guidelines. > > > > > > > > > Really? I’ve found that declaring everything in advance makes for > > hard-to-read code. To take an example from code I’ve written (admittedly > > not C code - GML if anyone’s curious - but it might as well be), the first > > line of a function looked like this: > > > > var list, hashList, text, i, pluginname, pluginhash, realhash, url, handle, > > filesize, progress, tempfile, tempdir, failed, lastContact, isCached, env; > > > > Even broken onto multiple lines, declaring everything at once isn’t nice. > > For large functions (and some functions have to be large necessarily), > > declaring everything at the start just means a long list of variables and I > > would argue impairs code readability. > > > > You should declare variables when and where you need them. If everything is > > done at the top, you have to scroll up to check the type of a variable. It > > also means that now-unused variables are less obvious as the declarations > > are far away from the usage, so you probably won’t spot that it’s useless > > unless you look at your compiler warnings. > > > > Actually, a similar issue popped up in the code where that example was > > from. The language it was written in had some unfortunate properties, one > > of which was that variables not explicitly declared would instead be > > treated as properties of the current object. Because all the variables were > > declared at the start of the function, it was easy to miss the fact that > > some variables being used had not actually been declared. Of course this > > specific issue doesn’t exist in C, but it is an example of why having to > > declare all your variables at the start of a function isn’t really a good > > thing. > > > > If nothing else, I think we should use C99’s ability to declare variables > > between statements. It makes it more likely mistakes will be spotted, eases > > reading code, and as far as I am aware, is widely supported. > I really hate this. > Thanks
+1, can’t agree more. Thanks, Wei Dai > > > > -- > > Andrea Faulds > > http://ajf.me/ > > > > > > > > > > > > -- > > PHP Internals - PHP Runtime Development Mailing List > > To unsubscribe, visit: http://www.php.net/unsub.php > > > > > -- > PHP Internals - PHP Runtime Development Mailing List > To unsubscribe, visit: http://www.php.net/unsub.php
