PHP 实现无限级分类的方法

<?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 &#39;─&#39;
  * @param integer $pid 父级分类ID。默认为 0，表示顶级分类
  * @param integer $level level级，配合 $html 显示足够的缩进。默认为 1，表示顶级分类
  * @return [type]   [description]
  */
 static public function unlimitedForLevel($cate, $html = &#39;─&#39;, $pid = 0, $level = 1){
  $arr = array();
  foreach($cate as $v){
   if($v[&#39;pid&#39;] == $pid){
    $v[&#39;level&#39;] = $level;
    $v[&#39;html&#39;] = str_repeat($html, $level - 1);
    $arr[] = $v;
    $arr = array_merge($arr, $this->unlimitedForLevel($cate, $html, $v[&#39;id&#39;], $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 $pid 父级分类ID。默认为0，表示顶级分类
  * @return [type]  [description]
  */
 static public function unlimitedForlayer($cate, $name = &#39;child&#39;, $pid = 0){
  $arr = array();
  foreach($cate as $v){
   if( $v[&#39;pid&#39;] == $pid){
    $v[$name] = self::unlimitedForlayer($cate, $name, $v[&#39;id&#39;]);
    $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[&#39;id&#39;] == $id){
    $arr[] = $v;
    $arr = array_merge(self::getParents($cate, $v[&#39;pid&#39;]), $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[&#39;pid&#39;] == $pid){
    $arr[] = $v[&#39;id&#39;];
    $arr = array_merge($arr, self::getChildrenId($cate, $v[&#39;id&#39;]));
   }
  }
  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[&#39;pid&#39;] == $pid){
    $arr[] = $v;
    $arr = array_merge($arr, self::getChildren($cate, $v[&#39;id&#39;]));
   }
  }
  return $arr;
 }
}
?>