PHP使用static声明静态变量计算层级数据

	private function _getCategoryName($data,$kg=‘‘){
		
		static $num = 1;
		static $retrun = array();
		
		if(!empty($data)){
			foreach ($data as $key => $value){
				$retrun[] = $num++.‘.‘.$kg.$value[‘name‘];
				if(!empty($value[‘children‘])){
					$this->_getCategoryName($value[‘children‘],$kg.‘——‘);
				}
			}
		}
		
		return $retrun;
	}