PHP Sort Array (Chatlog) by date (keep order of equivalent dates) -

i have chatlog composed of date , actual entry after 2 spaces. need sort time of entry, keep order of entries same when dates equivalent.

array (     [0] => '6/4 17:01:30.001  x'     [1] => '6/4 17:01:30.003  b'     [2] => '6/4 17:01:30.003  c'     [3] => '6/4 17:01:30.003  a'     [4] => '6/4 17:01:30.002  y' ) 

i tried couple of things, creating multidimensional array splitted in dates values sorting couple of different algorithms i'm pretty sure there must easy, , obvious way without multiple loops.

the result should this:

array (     [0] => '6/4 17:01:30.001  x'     [4] => '6/4 17:01:30.002  y'     [1] => '6/4 17:01:30.003  b'     [2] => '6/4 17:01:30.003  c'     [3] => '6/4 17:01:30.003  a' ) 

we can take advantage of fact date string sort in correct order. use key , ksort:

// starting array $aarray = array(     '6/4 17:01:30.001  x',     '6/4 17:01:30.002  y',     '6/4 17:01:30.003  b',     '6/4 17:01:30.003  c',     '6/4 17:01:30.003  a' );  // parse out date , use key. there might better regex use here, works... $akeyed = array(); foreach($aarray $value) {     preg_match('/([0-9]*\/[0-9]* [0-9]*:[0-9]*:[0-9]*\.[0-9]*)  (.*)/', $value, $amatches);     $akeyed[$amatches[1]][] = $amatches[0]; }  // sort key. ksort($akeyed);  // iterate keyed array values output array. order preserved since appended things value of keyed array in correct order. $aout = array(); foreach($akeyed $avalue) {     foreach($avalue $value)     {         // although there t2 loops, total number of iterations same single loop above.         $aout[] = $value;     } }  // print results. var_export($aout); 

output:

array (   0 => '6/4 17:01:30.001  x',   1 => '6/4 17:01:30.002  y',   2 => '6/4 17:01:30.003  b',   3 => '6/4 17:01:30.003  c',   4 => '6/4 17:01:30.003  a', )