arrays - Slow performance with cumulative count in PHP -

i have performance issues in chartcontroller. have 2 arrays: 1 array dates , 1 array entities contain date. want cumulative count date values of entities.

i have bit of code it's slow (i have wait 3 - 4 seconds 68k rows in data array).

my code:

// loop through sql results , count on date     foreach ($result $row) {         foreach ($dates $date => $value) {             // $row['appointmentdate'] datetime object             if ($date >= $row['appointmentdate']->format('ymd')) {                 $dates[$date]++;             }         }     } 

is there smarter / better / faster way achieve this?

// edit

jack gived me push needed , solved performance issue.

the code above took 38000 ms complete, code beneath 5700ms.

    usort($result, function($a, $b) {         return $a['appointmentdate'] > $b['appointmentdate'];     });      // loop through sql results , count on date     ($i = 0; $i++; $i <= count($result)) {         $i++;         $dates[$result[$i]['appointmentdate']->format('ymd')] = $i;     } 

thanks jack!

yes. can achieve better performance sorting 2 arrays before doing comparison. 2 arrays ordered can avoid doing n*m loop, , stay on n+m complexity (plus n*log n , m*log m sorting, anyway less n*m)