Post请求中的索引未定义


Undefined Index in Post request

我不知道为什么我得到这个奇怪的错误!

PHP注意:未定义的索引:refId在/var/www/echo. PHP第5行

我得到控制台输出,但不能回显refId。我做错什么了吗?

<?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>

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>

当我进行测试时,没有抛出任何错误,也没有执行Ajax。

发生这种情况是因为没有设置变量。使用isset

<?php
$rollUrl=34;
if(isset($_POST['refId'])) {
$refId=$_POST['refId'];
echo $refId;
}
?>

:您应该将refId作为名称属性分配给任何输入字段,以恢复用户的输入。

<input type="text" name="refId" />