# Array access on function returns - Thread: https://externals.io/message/37137 - Original archive: https://news-web.php.net/php.internals/37137 - Started by Kalle Sommer Nielsen on 2008-04-18T17:40:18+00:00 - Messages: 7 - Reply by email to internals@lists.php.net - More for agents: search with https://externals.io/search.md?q={query} · JSON API at https://externals.io/api · documentation at https://externals.io/llms.txt --- ## #37137 — Kalle Sommer Nielsen — 2008-04-18T17:40:18+00:00 URL: https://externals.io/message/37137#37137 Hey Internals I've been wondering for quite some time why PHP doesn't allow you to access arrays when you assign it to a value like in Javascript: function ArrayTest(Array $range) { return($range); } $range = Array(1337 => Array('Hello World')); echo ArrayTest($range)[1337}; I would really like to see this introduced in PHP sometime (Perhaps as an extra addition to 5.3's new and sleek features). This is very useful in a few areas and can save a few lines of code here and there. unfortunately Im not a C Programmer myself else I've would have provided a patch for this =/ Cheers Kalle Sommer Nielsen Zend Certified Engineer --- ## #37138 — Sam Barrow — 2008-04-18T18:26:25+00:00 URL: https://externals.io/message/37137#37138 · In reply to: #37137 > Hey Internals > > I've been wondering for quite some time why PHP doesn't allow you to access > arrays when you assign it to a value like in Javascript: > > function ArrayTest(Array $range) > { > return($range); > } > > $range = Array(1337 => Array('Hello World')); > > echo ArrayTest($range)[1337}; I was just about to write an email asking this same exact question this afternoon. This could be very useful, I don't see any reason not to have it. > > I would really like to see this introduced in PHP sometime (Perhaps as > an extra addition to 5.3's new and sleek features). > > This is very useful in a few areas and can save a few lines of code > here and there. > > unfortunately Im not a C Programmer myself else I've would have > provided a patch for this =/ > > > Cheers > > Kalle Sommer Nielsen > Zend Certified Engineer --- ## #37143 — Arvids Godjuks — 2008-04-19T06:59:12+00:00 URL: https://externals.io/message/37137#37143 · In reply to: #37138 2008/4/18, Sam Barrow : > > > > […] > access > > […] > > I was just about to write an email asking this same exact question this > afternoon. This could be very useful, I don't see any reason not to have > it. > > > […] > > > -- > > > > You now, PHP has it's own way of implementing this - just use list() function ArrayTest(Array $range) { return($range); } $range = Array('Hello World', 'Hello Me!'); list( , $greetMe) = ArrayTest($range); echo $greet; Although you example can't be implemented via list() because you key has insane value, but usualy we are stuck with few keys with sensible values like 0, 1, 2, 3. And you should realy return a string then, not an array. I never had a situation where list() couldn't help. And don't return a big array because of one value - that will help saving memory :) That's against. Well, I have an argument also for this one. It could realy help then returning multidemensional arrays or if an array of objects is returned // $object is some object witch contains a lot of other objects in it's properties function getObjectList($object) { $objectList = array(); foreach ($object as $value){ if (is_object($value)){ $objectList[get_class($value)] = $value; } } return $objectList; } // Let's assume we know for sure that object with name we know exists $myObject = new SomeCoolObject(); $result = getObjectList($myObject)['db']->query($sql)->execute(); Well, a stupid one example. So to me it is a little pointless, because you just can't check if key exists and that will be a warning. So it is very disputeable if we need it. --- ## #37146 — Kalle Sommer Nielsen — 2008-04-19T17:12:19+00:00 URL: https://externals.io/message/37137#37146 · In reply to: #37143 Hi Arvids Quoting Arvids Godjuks : > 2008/4/18, Sam Barrow : > > […] > You now, PHP has it's own way of implementing this - just use list() > > function ArrayTest(Array $range) { > return($range); > } > > $range = Array('Hello World', 'Hello Me!'); > list( , $greetMe) = ArrayTest($range); > echo $greet; I think it would be more suitable to have the array access syntax insted of the list(, , , $value) syntax, it helps readability for example. > > Although you example can't be implemented via list() because you key has > insane value, but usualy we are stuck with few keys with sensible values > like 0, 1, 2, 3. And you should realy return a string then, not an array. I > never had a situation where list() couldn't help. And don't return a big > array because of one value - that will help saving memory :) That's against. > > Well, I have an argument also for this one. > It could realy help then returning multidemensional arrays or if an array of > objects is returned > > // $object is some object witch contains a lot of other objects in it's > properties > function getObjectList($object) { > $objectList = array(); > foreach ($object as $value){ > if (is_object($value)){ > $objectList[get_class($value)] = $value; > } > } > return $objectList; > } > > // Let's assume we know for sure that object with name we know exists > $myObject = new SomeCoolObject(); > $result = getObjectList($myObject)['db']->query($sql)->execute(); > > Well, a stupid one example. So to me it is a little pointless, because you > just can't check if key exists and that will be a warning. So it is very > disputeable if we need it. > I think the usage of this would be in cases where you know the key exists, for example on `getimagesize()`: if(!getimagesize($some_image_url)[2] == IMAGETYPE_PNG) { die('Please supply a valid url to a png image...'); } Theres quite alot functions where you need to only get one key and insted of doing the list() (as written above) it would be nicer with syntax. Kalle Sommer Nielsen Zend Certified Engineer --- ## #37147 — Larry Garfield — 2008-04-19T21:51:54+00:00 URL: https://externals.io/message/37137#37147 · In reply to: #37146 > Hi Arvids > > Quoting Arvids Godjuks : > > […] > > […] > > I think the usage of this would be in cases where you know the key exists, > for example on `getimagesize()`: > > if(!getimagesize($some_image_url)[2] == IMAGETYPE_PNG) > { > die('Please supply a valid url to a png image...'); > } > > Theres quite alot functions where you need to only get one key and insted > of doing the list() (as written above) it would be nicer with syntax. > > > Kalle Sommer Nielsen > Zend Certified Engineer It is also useful if returning an object that implements ArrayAccess and lazy-loads data. $name = load_something($id)['name']; If using lazy-loading internally, that could offer very cheap access to the name property of the "something" object, with only a tiny bit of code. And it's really no more error prone than: $something = load($id); $name = $something['name']; Presumably you're doing some sort of automated error handling either way (trigger, exceptions, whatever.) -- Larry Garfield AIM: LOLG42 larry@garfieldtech.com ICQ: 6817012 "If nature has made any one thing less susceptible than all others of exclusive property, it is the action of the thinking power called an idea, which an individual may exclusively possess as long as he keeps it to himself; but the moment it is divulged, it forces itself into the possession of every one, and the receiver cannot dispossess himself of it." -- Thomas Jefferson --- ## #37148 — Mike Lively — 2008-04-20T05:12:15+00:00 URL: https://externals.io/message/37137#37148 · In reply to: #37137 On Fri, Apr 18, 2008 at 10:40 AM, Kalle Sommer Nielsen wrote: > Hey Internals > > I've been wondering for quite some time why PHP doesn't allow you to > access > arrays when you assign it to a value like in Javascript: My opinion on features such as this is that they provide too much opportunity to do things in a far less than optimal way. Another feature that was brought up (allowing method calls directly on the constructor) has the same problem. I realize that this type of functionality seems appealing when you need to operate on only one index of an array or when you only want to make a single method call on a newly instantiated object. But it is going to do it at the cost of readability (imo) and in some cases reduce the speed or flexibility of the code. If you reference the 'index' of the return value of a function you in effect have lost access to all other indexes in the array. So, as soon as you need another index you are forced to either rewrite your code to not access the method directly as an array, or you have to make another full function call to pull in the value. The same holds true for chaining function calls onto constructors. On the other hand it would be fun trying to track down exactly what you should be expecting from: $var = new Class()->call1()->property[0]->call2()[1]->wheeeeeee(); > function ArrayTest(Array $range) > { > return($range); > } > > $range = Array(1337 => Array('Hello World')); > > echo ArrayTest($range)[1337}; > > > I would really like to see this introduced in PHP sometime (Perhaps as an > extra addition to 5.3's new and sleek features). > > This is very useful in a few areas and can save a few lines of code here > and there. > > unfortunately Im not a C Programmer myself else I've would have provided a > patch for this =/ > > > Cheers > > Kalle Sommer Nielsen > Zend Certified Engineer --- ## #37149 — Wietse Venema — 2008-04-20T13:21:43+00:00 URL: https://externals.io/message/37137#37149 · In reply to: #37137 Kalle Sommer Nielsen: > Hey Internals > > I've been wondering for quite some time why PHP doesn't allow you > to access arrays when you assign it to a value like in Javascript: In many languages you get such functionality for free, because their parsers are written to accept: expression '[' expression ']' Thus, any expression that evaluates to an array can have '[]'. Javascript, Perl and C are just a few examples. The PHP parser is different. It requires a variable to the left of '['. Changing this is not as simple as changing one or two YACC rules. Wietse