//顶级ID为1 function make_tree($arr){ $refer = array(); $tree = array(); foreach($arr as $k => $v){ $refer[$v['id']] = & $arr[$k]; //创建主键的数组引用 } foreach($arr as $k => $v){ $pid = $v['pid']; //获取当前分类的父级id if($pid == 1){ $tree[] = & $arr[$k]; //顶级栏目 }else{ if(isset($refer[$pid])){ $refer[$pid]['subcat'][] = & $arr[$k]; //如果存在父级栏目,则添加进父级栏目的子栏目数组中 } } } return $tree; }