php 排序数组,拼接字符串

需求:

$data = array("appId" => 1, "username" => "xx", "mobile" => "183xxxx8952", "tid" => 1); 

把数组的参数按字母的先后顺序排列并用&拼接

eg:appId=1&mobile=183xxxx8952&tid=1&username=xx

Fun:

function genVerify($data) {
	ksort($data);
	$items = array();
	foreach ($data as $key => $value) {
		$items[] = $key . "=" . $value;
	}
	return join("&", $items);
}

$data = array(
	"appId" => 1, 
	"username" => "xx", 
	"mobile" => "183xxxx8952", 
	"tid" => 1
);
echo genVerify($data);

return:

appId=1&mobile=183xxxx8952&tid=1&username=xx