function maxNum($array) {
if (count($array) == 1) {
return $array[0];
}
$num = array_shift($array);
$maxNum = maxNum($array);
return $num > $maxNum ? $num : $maxNum;
}
$a = [1,4,6,3,8];
$res = maxNum($a);
var_dump($a);原文：https://www.cnblogs.com/jianzhaojing/p/12779575.html