Why PHP sucks

(July 8 2005)

Apparently I got linked by some PHP sites, and while there were a few well-reasoned comments here I mostly just got people who only knew PHP reacting like I told them their firstborn was ugly. These people tended to give variants on one or more themes:

• All environments have warts, so PHP is no worse than anything else in this respect
• I can work around PHP's problems, ergo they are not really problems
• You aren't experienced enough in PHP to judge it yet

As to the first, it is true that PHP is not alone in having warts. However, the lack of qualitative difference does not mean that the quantitative difference is insignificant.

Similarly, problems can be worked around, but languages/environments designed by people with more foresight and, to put it bluntly, clue, simply don't make the kind of really boneheaded architecture mistakes that you can't help but run into on a daily baisis in PHP.

Finally, as I noted in my original introduction, with PHP, familiarity breeds contempt. You don't need years of experience with PHP before an urge to get the hell out and into a more productive environment becomes almost overwhelming -- provided that you have enough experience to realize what that nagging lack of productivity is telling you when you go to consult the documentation for the fifth time in one morning.

Basically these all boil down to, "I don't have enough experience to recognize PHP's flaws because I haven't used anything better." Many years ago, I had this same attitude about Turbo Pascal: it was the only language I knew at the time, so anyone who pointed out its flaws was in for a heated argument.

There's nothing wrong with being inexperienced, as long as you have an open mind. If you do, try Spyce. Try RoR, if you must. Better toolkits are out there, for those who aren't satisfied with mediocrity.

I've done a fair bit of web development. I've written HTML-generating code in C CGI scripts, Cold Fusion, TCL (with OpenACS), ASP.NET, and, of course, Python with Spyce.

Two technologies I've steered clear of are any J2EE stack and PHP. I've seen enough of each to know that I'd be immensely frustrated with either. Briefly, although they are quite different, neither is elegant, and elegance counts.

Recently, though, I had to spend a few days extending a small amount of PHP code. (I'm just glad for two of those qualifiers: "few" and "small.") The more I used it, the less impressed I was, which is why I don't think a longer experience would make this post any more favorable to PHP.

This is far from an exhaustive list. It may have some reasoning in common with other voices of reason, but I'm writing this primarily from a Python developer's perspective. So, I won't waste time bashing PHP for being dynamic, which some Java zealots do; nor will I fault it for mixing code and markup, which also has its uses (and Spyce recognizes this). PHP's problems are much, much deeper.

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First, let's try to be a bit more specific. Does PHP the language suck, or does PHP the environment suck?

They both suck.

In fact, they suck for the same reason: PHP-the-language and PHP-the-environment both grew by accretion of random features, not by any purposeful design for orthogonality. So you have idiot "features" like magic quotes ("Assuming it to be on, or off, affects portability. Use get_magic_quotes_gpc() to check for this, and code accordingly) and register globals (same disclaimer applies, only more so).

Trying to write "portable" php code is such a disaster that it's no wonder almost nobody tries; you can't even code for a least-common-denominator version because (a) so much is subject to change on the whim of the site's config file and (b) even if it weren't, the PHP designers change the defaults almost as often, even within minor version releases. (E.g., the registerglobals change for 4.2.)

The PHP community realizes this to a degree, even if the fanboys won't admit it. PHP5 uptake is almost as glacial as MySQL4 was/is because it breaks so much code. One of the biggest ways is, "all your copy-on-assign code, isn't anymore."

That bears explaining if you haven't coded in PHP4: any time you make an assignment in PHP4, what other languages would call a "deep copy" is performed. So you might naiively expect this code to add a new key/value pair to the associative array at $a[0]:

<?
$a = array(array('foo' => 'bar'));
foreach ($a as $item) {
   $item['new key'] = 'new value';
}
print_r($a);
?>

This, of course, changes $a not at all, because the assignment to $item is a deep copy. (It's also slow as hell if the items you're deep-copying are substantial.) The workarounds for this are truly ugly.

This changes completely in PHP5, which is a good thing, unless you're trying to upgrade an existing body of code. That's not a small "unless;" if you weren't using PHP4, there's really no excuse to start out in PHP5 instead of Spyce or CherryPy or Rails.

Even with a willingness to break backwards compatibility, a lot of broken behavior persists in PHP5. For instance, since I brought up PHP arrays: an array in PHP is really a map. When you're using it as a linear array, it's really mapping keys 0, 1, etc. to your values. (I don't want to know what it does when you're using it as a 2D array.) This might seem like a good idea, until you spend about two seconds thinking about it, at which point those of you who have had a basic introduction to data structures will be thinking, "What the hell? The performance will SUCK!" And you are entirely correct. The only other language I can think of that does this is AWK, and it was a bad idea there, too, but less of a problem since, well, when was the last time you wrote an AWK script longer than 10 lines?

PHP-the-language also shares with Perl the unfortunate tendency to guess what the programmer "really meant" instead of raising errors. (String where an integer makes more sense? No problem, we'll just throw in zero!) Unlike perl, there's no "use strict" option to mitigate this.

I could keep going, on how, for instance, the PHP environment doesn't give you any way to have a single, multithreaded long-running process, which is probably why you see so much PHP code that sticks everything into the session object. Or how PHP's string processing library adopted the C stdlib functions without improving on them. Or a dozen things, but a comprehensive enumeration of PHP design flaws would be a daunting task indeed.

In short, PHP sucks because, PHP's authors are prone to confuse "pragmatism" (a fine design goal, if done well) with "adding random features without considering how they impact the language as a whole." Thus, its authors have found it necessary to correct obvious flaws in both minor and major releases, with the result that the recent PHP5 breaks with the past to an unprecedented degree while still leaving many fundamental flaws un-addressed. I don't know if this is because they didn't recognize those flaws, or more likely, because they were willing to impose "requires a lot of pain to upgrade" but not "requires a complete re-write."

Ian Bicking wrote that "Python could have been PHP" (in popularity for web development). If I were a PHP developer, I'd be pretty disenchanted with how the language has evolved; I don't think it's impossible that Python could have a second chance.