比较少的几行代码实现的无限递归
表字段 id,name,pid,level
function array2list($array,$pid = 0,$level = 1){
static $list = [];
foreach($array as $v){
if($v['pid'] == $pid){
$v['level'] = $level;
$list[] = $v;
array2list($array,$v['id'],$level++);
}
}
return $list;
}