在PHP中引用比较变量 - Referencing the Compared Variable in PHP

这感觉像是一个非常愚蠢的问题，但我一直在想我是否做错了:

if($payment->shipping_state OR $payment->shipping_province)
    {
        $request['SHIPTOSTATE'] = isset($payment->shipping_state) ? $payment->shipping_state : $payment->shipping_province;
    }

是否有一个关键字/更简单的方法将$request['SHIPTOSTATE']设置为存在的变量，因为我已经确认了两者中的一个确实存在?

类似:

if ($payment->shipping_state OR $payment->shipping_province)
{
  $var = $this;
}

$data = (!empty($payment->shipping_state))?$payment->shipping_state:$payment->shipping_province;
if (!empty($data))
    $request['SHIPTOSTATE'] = $data;