php - Post 请求中未定义索引

Question

我不知道为什么会收到这个奇怪的错误!

PHP Notice: Undefined index: refId in /var/www/echo.php on line 5

我正在获取控制台输出，但无法回显 refId。我在这里做错了什么吗？

<?php
    $rollUrl = 34;
    $refId = $_POST['refId'];
    echo $refId;
?>

<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
<script>
    $.ajax({
        url:'echo.php',
        type: 'POST',
        data: { 'refId': "<?php echo $rollUrl ?>" },
        success: function(response){
            console.log('Getting response');
        }
    }); 
</script>

Answer 1

请参阅下面代码中的注释:

<?php
$rollUrl = 34;

//Only try to process POST if there is something posted *and* refId exists
if (count($_POST) > 0 && isset($_POST['refId'])) { 
  $refId = $_POST['refId'];
  echo $refId;
  //Exit after echoing out the refId so that the HTML below does not also get returned.
  exit();
}
?>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
<script>
    $.ajax({
        url:'echo.php',
        type: 'POST',
        data: { 'refId': "<?php echo $rollUrl ?>" },
        success: function(response) {
            //Updated log to show the actual response received.
            console.log('Getting response of "' + response + '"');
        }
    }); 
</script>

当我测试时没有抛出任何错误并且 Ajax 正在执行时，这对我有用。