Online PHP editor | refs for nQcDS

<?php $arr=array( array('amount'=>100,'date'=>'2014-03-29'), array('amount'=>120,'date'=>'2014-03-30'), array('amount'=>200,'date'=>'2014-03-31'), array('amount'=>0,'date'=>'2014-04-31'), array('amount'=>0,'date'=>'2014-05-31') ); function sd($a,$b) {if($a['date'] == $b['date']) return 0; return $a['date'] >$b['date'] ? 1 : -1;} usort($arr, 'sd'); $amount = 0; foreach($arr as &$item) { $amount += $item['amount']; $item['amount'] = $amount; } print_r($arr); $arr =array(100,100,100,15,20,50,70,100,100,);