递归实现无限极分类列表和二级菜单的展示

/**
     * 递归的方式实现无限极分类
     * @param $arr
     * @param int $pid
     * @param int $level
     * @return array
     */
    function getTree($arr, $pid = 0, $level = 0)
    {

        static $list = [];
        foreach ($arr as $key => $v) {
            if ($v['pid'] == $pid) {
                $v['level']=$level;
                $list[]=$v;
                unset($arr[$key]);
                $this->getTree($arr,$v['id'],$level+1);
            }
        }
        return $list;
    }

 组装二级分类

public static function tree($table,$p_id='100000') {
    $tree = array();
    foreach($table as $row){
        if($row['pid']==$p_id){
            $tmp = self::tree($table,$row['id']);
            if($tmp){
                $row['children']=$tmp;
            }else{
                $row['leaf'] = true;
            }
            $tree[]=$row;
        }
    }
    Return $tree;
}