#21728 [Opn]: Additional (kindly weird example) for sort()

ID: 21728 Updated by: philip@php.net Reported By: andrey@php.net Status: Open Bug Type: Documentation problem Operating System: All -PHP Version: 4.3.0 +PHP Version: 4.4.0-dev New Comment: How about: <?php $arr1 = array("a","b","4",5,4,"true","TRUE",true, false, "c"); sort($arr1); var_dump($arr1); ?> Which gives: array(10) { [0]=> bool(false) [1]=> string(4) "TRUE" [2]=> string(1) "a" [3]=> string(4) "true" [4]=> bool(true) [5]=> string(1) "b" [6]=> string(1) "c" [7]=> int(4) [8]=> string(1) "4" [9]=> int(5) } Which is weird as "4" looks misplaced. For example in this: <?php $arr1 = array("a","b","4",5,4,"true","TRUE",true, false, "c", "d"); sort($arr1); var_dump($arr1); ?> We get different results (all I added was "d" to the end): array(11) { [0]=> bool(false) [1]=> string(1) "4" [2]=> string(4) "TRUE" [3]=> string(1) "a" [4]=> string(1) "b" [5]=> string(1) "c" [6]=> string(1) "d" [7]=> string(4) "true" [8]=> bool(true) [9]=> int(4) [10]=> int(5) } Notice the different order, is this a genuine bug? Previous Comments: ------------------------------------------------------------------------ [2003-01-18 10:26:27] andrey@php.net Today I closed bug #21444. The user has to master the type juggling to know the expected output. I think that it is good idea to add it's example as comprehensive one. The script goes here (the explanation is after it) : <?php $arr1 = array("a","b","c","d","4",5,4,"true","TRUE",true); sort($arr1); var_dump($arr1); ?> The output is : array(10) { [0]=> bool(true) [1]=> int(4) [2]=> string(1) "4" [3]=> string(4) "TRUE" [4]=> string(1) "a" [5]=> string(1) "b" [6]=> string(1) "c" [7]=> string(1) "d" [8]=> string(4) "true" [9]=> int(5) } It may look strange - why (int)5 is after all the strings. This is because "4" is lower than (int) 5, "4" is before "true" and "true" is before 5. The first 2 are obvious, the third one is not. But it is ok. It's better not to mix types in the array. If 5 is changed to "5" then "5" goes right after "4". Thanks ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=21728&edit=1