php递归实现无限分类的方法

本文实例讲述了php递归实现无限分类的方法。分享给大家供大家参考。具体如下：

    <?php
    $rows = array(
      array(
        'id' => 1,
        'name' => 'dev',
        'parentid' => 0
      ),
      array(
        'id' => 2,
        'name' => 'php',
        'parentid' => 1
      ),
      array(
        'id' => 3,
        'name' => 'smarty',
        'parentid' => 2
      ),
      array(
        'id' => 4,
        'name' => 'life',
        'parentid' => 0
      ),
      array(
        'id' => 5,
        'name' => 'pdo',
        'parentid' => 2
      ),
      array(
        'id' => 6,
        'name' => 'pdo-mysql',
        'parentid' => 5
      ),
      array(
        'id' => 7,
        'name' => 'java',
        'parentid' => 1
      )
    );
    // 72648
    // 84072
    function findChild(&$arr,$id){
      $childs=array();
       foreach ($arr as $k => $v){
         if($v['parentid']== $id){
           $childs[]=$v;
         }
      }
      return $childs;
    }
    function build_tree($root_id){
      global $rows;
      $childs=findChild($rows,$root_id);
      if(empty($childs)){
        return null;
      }
      foreach ($childs as $k => $v){
        $rescurTree=build_tree($v[id]);
        if( null !=  $rescurTree){ 
        $childs[$k]['childs']=$rescurTree;
        }
      }
      return $childs;
    }
    $tree=build_tree(0);
    echo memory_get_usage();
    print_r($tree);
    ?>

希望本文所述对大家的php程序设计有所帮助。