Re: Re: Question about superglobals

I disagree, although you do have a very good point. But simple logic flaws can cause huge bugs regardless, whether it would be because of a superglobal or any other programmer error. Although you have a point, the only place where we disagree is that I think the benefits outweigh the risks. On Fri, 2007-11-16 at 20:34 -0800, Rasmus Lerdorf wrote: > Sam Barrow wrote: > > You say that superglobals were not designed to be user defined, think > > about it, the concept of a superglobal is present in C and C++, two of > > the maturest and strictest languages around. > > The concept of having to declare your globals is unique to PHP, true. > It is one of the oldest features in PHP too. So, a little history... > > Back in 1989 I spent at least a month chasing a bug at a company in > Canada called Bell Northern Research. It was a weird crash bug in a > rather complicated system. It was mostly written in C and after pouring > through reams and reams of code printouts day after day, I finally found > that it was due to a side effect of some obscure function overwriting a > global variable that was used in a completely different area of the > code. That particular feature of the C language was not popular with me > for a long time after that, and when it came time to work out function > scoping of variables in PHP, I made sure to not make that same mistake. > > And yes, because PHP is a web language and there are common aspects of a > web request that many functions will need to act on, it makes sense to > have a finite number of clearly labeled global arrays like _GET, _POST, > etc. And later on, being able to access any global via $_GLOBALS was > added, but again, it is a very descriptive name and not likely to result > in someone mistaking it for something else and ending up with strange > side effects. > > I am definitely not in favor of destroying what I consider a rather good > design decision just to avoid a couple of keystrokes here and there. So > yes, you will have to keep adding "global $cfg;" to your functions, or > accessing it via $_GLOBALS['cfg'], and when you forget, it won't work. > And yes, you will grumble a bit at that, but that is nothing compared to > trying to find a bug caused by a global side effect in someone else's > code. Trust me, you will grumble a lot more at that. > > -Rasmus >