PHP 无限级分类

<?php
/**
 * 无限级分类 类
 */
class category{
 /**
  * 返回一维数组
  * @param [type] $cate 要递归的数组
  * @param string $html 子级分类前要显示的缩进符号。默认 '─'
  * @param integer $pid 父级分类id。默认为 0，表示*分类
  * @param integer $level level级，配合 $html 显示足够的缩进。默认为 1，表示*分类
  * @return [type]   [description]
  */
 static public function unlimitedforlevel($cate, $html = '─', $pid = 0, $level = 1){
  $arr = array();
  foreach($cate as $v){
   if($v['pid'] == $pid){
    $v['level'] = $level;
    $v['html'] = str_repeat($html, $level - 1);
    $arr[] = $v;
    $arr = array_merge($arr, $this->unlimitedforlevel($cate, $html, $v['id'], $level + 1));
   }
  }
  return $arr;
 }
 /**
  * 返回多维数组
  * @param [type] $cate 要递归的数组
  * @param string $name 子级分类在父分类数组中的 key
  * @param integer $pid 父级分类id。默认为0，表示*分类
  * @return [type]  [description]
  */
 static public function unlimitedforlayer($cate, $name = 'child', $pid = 0){
  $arr = array();
  foreach($cate as $v){
   if( $v['pid'] == $pid){
    $v[$name] = self::unlimitedforlayer($cate, $name, $v['id']);
    $arr[] = $v;
   }
  }
  return $arr;
 }
 /**
  * 传递子分类id返回所有父级分类
  * @param [type] $cate 要递归的数组
  * @param [type] $id 子分类id
  * @return [type]  [description]
  */
 static public function getparents($cate, $id){
  $arr = array();
  foreach($cate as $v){
   if($v['id'] == $id){
    $arr[] = $v;
    $arr = array_merge(self::getparents($cate, $v['pid']), $arr);
   }
  }
  return $arr;
 }
 /**
  * 传递父级分类id返回所有子分类id
  * @param [type] $cate 要递归的数组
  * @param [type] $pid 父级分类id
  * @return [type]  [description]
  */
 static public function getchildrenid($cate, $pid){
  $arr = array();
  foreach($cate as $v){
   if($v['pid'] == $pid){
    $arr[] = $v['id'];
    $arr = array_merge($arr, self::getchildrenid($cate, $v['id']));
   }
  }
  return $arr;
 }
 /**
  * 传递父级分类id返回所有子级分类
  * @param [type] $cate 要递归的数组
  * @param [type] $pid 父级分类id
  * @return [type]  [description]
  */
 static public function getchildren($cate, $pid){
  $arr = array();
  foreach($cate as $v){
   if($v['pid'] == $pid){
    $arr[] = $v;
    $arr = array_merge($arr, self::getchildren($cate, $v['id']));
   }
  }
  return $arr;
 }
}
?>