PHP基于变量的引用实现的树状结构

直接上代码：

 function aryTree($ary, $tagId = 'id', $tagPid = 'pid', $tagSub = '_sub') {

     if(is_array($ary)) {

         $refer = array(); // 创建基于主键(id)的数组引用(映射)

         foreach ($ary as $k => $v) {
             $refer[$v[$tagId]] =& $ary[$k]; // "引用":不同的变量名访问同一个内容
         }

         foreach ($ary as $k => $v) {
             if (isset($refer[$v[$tagPid]])) {
                 $parent =& $refer[$v[$tagPid]];
                 $parent[$tagSub][$v[$tagId]] =& $ary[$k];
                 unset($ary[$k]);
             }
         }
         unset($refer);
     }

     return $ary;
 }

以下Function是可设置父级级别的代码：

 function aryTree($ary, $id = 'id', $pid = 'pid', $sub = '_sub', $root = 0) {

     $tree = array();

     if(is_array($ary)) {

         $refer = array();

         foreach ($ary as $k => $v) {
             $refer[$v[$id]] =& $ary[$k];
         }

         foreach ($ary as $k => $v) {

             $parentId =  $v[$pid];

             if ($root == $parentId) {

                 $tree[$v[$id]] =& $ary[$k];

             }else{

                 if (isset($refer[$parentId])) {
                     $parent =& $refer[$parentId];
                     $parent[$sub][$v[$id]] =& $ary[$k];
             　　　　 unset($ary[$k]);
                 }
             }
         }
         unset($refer, $ary);
     }

     return $tree;
 }