$a1=array(1,2,3);
$a2=array(4,5,6,7,8,9);
$a3=array(10,11);
$a4=array(12,13,14,15);
$maxlen = max(count($a1), count($a2), count($a3), count($a4));
$a = array($a1, $a2, $a3, $a4);
$SUM = array();
for ($i = 0; $i < $maxlen; $i++) {
foreach ($a as $arr) {
if (array_key_exists($i, $arr)) {
$SUM[] = $arr[$i];
}
}
}
var_dump($SUM);
出力:
配列(15) { [0]=> int(1) [1]=> int(4) [2]=> int(10) [3]=> int(12) [4]=> int(2) [5]=> int(5) [6]=> int(11) [7]=> int(13) [8]=> int(3) [9]=> int(6) [10]=> int(14) [11]=> int(7) [12]=> int(15) [13]=> int(8) [14]=> int(9) }