我有一个基于usermeta字段查找user\\u id的小例程。。

$scaleData = json_decode($reading, TRUE);
$deviceid = $scaleData["imei"];
echo $deviceid; // check to confirm is working. Yup

$WhoIsUser = get_users(
  array(
   \'meta_key\' => \'deviceid\',
   \'meta_value\' => \'$deviceid\'
 )
);

$CurrentUser = $WhoIsUser[0]->ID;
echo $CurrentUser; //returns nothing

但如果我切换“meta\\u value”=>45455（使用已知的设备号），它将返回ID，没有问题。我已经尝试了$deviceid和“$deviceid”我缺少什么？

$WhoIsUser = get_users(
  array(
   \'meta_key\' => \'deviceid\',
   \'meta_value\' => "$deviceid"
 )
);