1,'name'=>'电脑','pid'=>0), array('id'=>2,'name'=>'手机','pid'=>0), array('id'=>3,'name'=>'笔记本','pid'=>1), array('id'=>4,'name'=>'台式机','pid'=>1), array('id'=>5,'name'=>'智能机','pid'=>2), array('id'=>6,'name'=>'功能机','pid'=>2), array('id'=>7,'name'=>'超级本','pid'=>3), array('id'=>8,'name'=>'游戏本','pid'=>3), ); /*======================非递归实现========================*/ $tree = array(); //第一步，将分类id作为数组key,并创建children单元 foreach($categories as $category){ $tree[$category['id']] = $category; $tree[$category['id']]['children'] = array(); } //第二步，利用引用，将每个分类添加到父类children数组中，这样一次遍历即可形成树形结构。 foreach($tree as $key=>$item){ if($item['pid'] != 0){ $tree[$item['pid']]['children'][] = &$tree[$key];//注意：此处必须传引用否则结果不对 if($tree[$key]['children'] == null){ unset($tree[$key]['children']); //如果children为空，则删除该children元素（可选） } } } ////第三步，删除无用的非根节点数据 foreach($tree as $key=>$category){ if($category['pid'] != 0){ unset($tree[$key]); } } print_r($tree); /*======================递归实现========================*/ $tree = $categories; function get_attr($a,$pid){ $tree = array(); //每次都声明一个新数组用来放子元素 foreach($a as $v){ if($v['pid'] == $pid){ //匹配子记录 $v['children'] = get_attr($a,$v['id']); //递归获取子记录 if($v['children'] == null){ unset($v['children']); //如果子元素为空则unset()进行删除，说明已经到该分支的最后一个元素了（可选） } $tree[] = $v; //将记录存入新数组 } } return $tree; //返回新数组 } print_r(get_attr($tree,0)); |