#34073 [NEW]: Is the array operator ([]) really right-associative?

From: phpbugs at majiclab dot com Operating system: n/a PHP version: Irrelevant PHP Bug Type: Documentation problem Bug description: Is the array operator ([]) really right-associative? Description: ------------ I either don't understand why the [] operator is claimed to be right-associative, or there's a documentation error (http://ca.php.net/operators) On that page, the following is claimed: Operator: [] Associativity: Right From my understanding of the online documentation, that means that for the following code: <?php $c = $a[1][2]; ?> The following "precedence" tree would be used: 1. [2] 2. [1] 3. = But obviously it would be processed more like this: 1. [1] 2. [2] 3. = The reasoning being that PHP needs to know what array you're accessing an index for, so the starts from the and goes on to the right. If it started with [2], then it doesn't know what array to access yet until it accesses the next operator and says "oh ok, let's get index 2 from $a[1]". So needless to say I am a little confused by the documentation? In my mind, [] should either be non-associative or at least left-associative? Now, I only just thought that it might be referring to nested []: <?php $a = $b[$c[1]]; ?> But in my mind, anything within [...] is a whole expression unto itself. ie: <?php $a = $b[strtolower($c[1]) . '-stuff']; ?> So I can understand where [] can be right-associative when nested, but in my mind [] is more closely related to () than anything else. () forces precedence, and everything inside of the () has not relation/cares to anything outside of it, same with []. Anything inside the [] has nothing to do with anything outside of it. Anyway, I just thought the documentation was possibly unclear on this, and I think it could be because of the complication of the [] compared to other operators. For a final example: <?php $a = $b = 1; $a[$b[1]]; ?> In both cases the operand precedence goes from 1 => $b => $a. The operands are in the same order, but the [] wraps around the operands, whereas all the other operators do not. I think this could be the cause of the confusion or lack of specific examples/documentation on the website. In any case, I think there should at least be some clarification, or maybe I am completely misunderstanding the [] operator? I would hope not since I'm a fairly experienced PHP developer, but in any case I will admit that I may have the whole thing completely wrong! Reproduce code: --------------- n/a Expected result: ---------------- n/a Actual result: -------------- n/a -- Edit bug report at http://bugs.php.net/?id=34073&edit=1 -- Try a CVS snapshot (php4): http://bugs.php.net/fix.php?id=34073&r=trysnapshot4 Try a CVS snapshot (php5.0): http://bugs.php.net/fix.php?id=34073&r=trysnapshot50 Try a CVS snapshot (php5.1): http://bugs.php.net/fix.php?id=34073&r=trysnapshot51 Fixed in CVS: http://bugs.php.net/fix.php?id=34073&r=fixedcvs Fixed in release: http://bugs.php.net/fix.php?id=34073&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=34073&r=needtrace Need Reproduce Script: http://bugs.php.net/fix.php?id=34073&r=needscript Try newer version: http://bugs.php.net/fix.php?id=34073&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=34073&r=support Expected behavior: http://bugs.php.net/fix.php?id=34073&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=34073&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=34073&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=34073&r=globals PHP 3 support discontinued: http://bugs.php.net/fix.php?id=34073&r=php3 Daylight Savings: http://bugs.php.net/fix.php?id=34073&r=dst IIS Stability: http://bugs.php.net/fix.php?id=34073&r=isapi Install GNU Sed: http://bugs.php.net/fix.php?id=34073&r=gnused Floating point limitations: http://bugs.php.net/fix.php?id=34073&r=float No Zend Extensions: http://bugs.php.net/fix.php?id=34073&r=nozend MySQL Configuration Error: http://bugs.php.net/fix.php?id=34073&r=mysqlcfg