PHP 通过百度API 实现通过城市名称获取经度

$city = $_GET['city'];
print_r(getjw($city));
/**
* $city 需要查询的地址
* $key 百度开发者账号
*/
function getjw($city){
$key = "";
$url = "http://api.map.baidu.com/geocoder?address=$city&output=json&key=$key";
$result = file_get_contents($url);
$json = json_decode($result,true);
$var = $json['result']['location'];
return $var;
}