问如何在cURL请求中使用PHP发送空数组值？

EN

//Post data 
$data = array('fieldValues'=>array(),'token'=>'XXXxXX7.......');

$postUrl = 'http://<REST API URL>/<service url>';
$postdata = http_build_query(json_decode(file_get_contents("php://input"), true));

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $postUrl);
curl_setopt($ch, CURLOPT_POST, 1);

// in real life you should use something like:
 curl_setopt($ch, CURLOPT_POSTFIELDS, 
          $postdata);

// receive server response ...
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

$server_output = curl_exec ($ch);

curl_close ($ch);
echo $server_output;
exit;