PHP转化格式化的字符串为数组

/**
 * 转化格式化的字符串为数组 
 * @param string $tag 要转化的字符串,格式如:"id:2;cid:1;order:post_date desc;"
 * @return array 转化后字符串<pre>
 * array(
 *  'id'=>'2',
 *  'cid'=>'1',
 *  'order'=>'post_date desc'
 * )
 */
function sp_param_lable($tag = ''){
	$param = array();
	$array = explode(';',$tag);
	foreach ($array as $v){
		$v=trim($v);
		if(!empty($v)){
			list($key,$val) = explode(':',$v);
			$param[trim($key)] = trim($val);
		}
	}
	return $param;
}