PHP递归遍历多维数组实现无限分类的方法

本文实例讲述了PHP递归遍历多维数组实现无限分类的方法。分享给大家供大家参考，具体如下：

<?php
   //$data[]=array('id'=>1,'parentid'=>0,'name'=>'中国','img'=>'52091199');   
   $data[]=array('id'=>1,'parentid'=>0,'name'=>'中国');   
   $data[]=array('id'=>2,'parentid'=>0,'name'=>'美国');   
   $data[]=array('id'=>3,'parentid'=>0,'name'=>'韩国');   
   $data[]=array('id'=>4,'parentid'=>1,'name'=>'北京');  
   $data[]=array('id'=>5,'parentid'=>1,'name'=>'上海');   
   $data[]=array('id'=>6,'parentid'=>1,'name'=>'广西');   
   $data[]=array('id'=>7,'parentid'=>6,'name'=>'桂林');   
   $data[]=array('id'=>8,'parentid'=>6,'name'=>'南宁');   
   $data[]=array('id'=>9,'parentid'=>6,'name'=>'柳州');  
   $data[]=array('id'=>10,'parentid'=>2,'name'=>'纽约');  
   $data[]=array('id'=>11,'parentid'=>2,'name'=>'华盛顿');  
   $data[]=array('id'=>12,'parentid'=>3,'name'=>'首尔');   
   $tree=build_tree($data,0);   
   //echo memory_get_usage();   
  print_r($tree); 
function findChild(&$arr,$id){  
  $childs=array();  
  foreach ($arr as $k => $v){ 
    if($v['parentid']== $id){    
     $childs[]=$v;   
    }  
  }  
  return $childs; 
} 
function build_tree($rows,$root_id){  
  $childs=findChild($rows,$root_id);  
  if(empty($childs)){   
    return null;  
  } 
foreach ($childs as $k => $v){  
  $rescurTree=build_tree($rows,$v['id']);  
  if( null != $rescurTree){  
  $childs[$k]['childs']=$rescurTree;  
  } 
 }  
  return $childs; 
 }
?>

运行结果：

Array
( 
  [0] => Array  
    (   
     [id] => 1   
     [parentid] => 0   
     [name] => 中国   
     [childs] => Array    
      (     
       [0] => Array      
        (       
         [id] => 4       
         [parentid] => 1       
         [name] => 北京      
         )     
       [1] => Array      
        (       
         [id] => 5       
         [parentid] => 1       
         [name] => 上海      
         )     
       [2] => Array      
        (       
         [id] => 6       
         [parentid] => 1       
         [name] => 广西       
         [childs] => Array        
           (         
             [0] => Array          
              (           
                [id] => 7           
                [parentid] => 6           
                [name] => 桂林          
               )         
             [1] => Array          
              (           
               [id] => 8           
               [parentid] => 6           
               [name] => 南宁          
               )         
              [2] => Array          
               (           
                [id] => 9           
                [parentid] => 6           
                [name] => 柳州          
                )        
              )      
            )    
         )  
       ) 
          [1] => Array  
           (   
            [id] => 2   
            [parentid] => 0   
            [name] => 美国   
            [childs] => Array    
               (     
                [0] => Array      
                (       
               [id] => 10       
               [parentid] => 2       
               [name] => 纽约      
                )     
              [1] => Array      
             (       
              [id] => 11       
              [parentid] => 2       
              [name] => 华盛顿      
              )    
           )  
        ) 
      [2] => Array  
        (   
          [id] => 3   
          [parentid] => 0   
          [name] => 韩国   
          [childs] => Array    
          (     
           [0] => Array      
             (       
            [id] => 12       
            [parentid] => 3       
            [name] => 首尔      
           )    
        )  
    )
)