- print_r: documentation ( source)
- array_values: documentation ( source)
<?php
$arr = array(
array('num'=>5,'period'=>3),
array('num'=>10,'period'=>3),
array('num'=>15,'period'=>9)
);
$temp = array();
foreach($arr as $item) {
list($n, $p) = array_values($item);
$temp[$p] = array_key_exists($p, $temp) ? $temp[$p]+$n : $n;
}
print_r($temp);
$arr = array();
foreach($temp as $p => $n)
$arr[] = array('num'=>$n, 'period'=>$p);
print_r($arr);