PHP echo JS包含PHP变量

Question

我有sendForm.php文件，这是使用PHPMailer发送表单的php。 在标签之间有回声，我需要在标签之间使用PHP变量。 这有可能吗？ 我知道这太结合了PHP和JS，但是我能做什么......我需要一个窗口弹出窗口，这也是我使用JS的原因。 echo本身只打印到网页本身。

$totalSize = ($totalSize/(1024*1024));
$totalSize = round($totalSize,2);

if(!$mail->Send()) {
   echo "Error sending form! You are trying to send too large files. Their size is: ", $totalSize, " MB";
   echo '<script type="text/javascript">alert("Error sending form! You are trying to send too large files. Their size is: ??? ");</script>';
   }

如何在JS内部打印$ totalSize变量代替第二个回声中的那些问号呢？ 谢谢你的帮助。 我还是个初学者。

Answer 1

if(!$mail->Send()) {
   echo "Error sending form! You are trying to send too large files. Their size is: ". $totalSize. " MB";
   echo '<script type="text/javascript">alert("Error sending form! You are trying to send too large files. Their size is: '. $totalSize. '");</script>';
   }

//我纠正了第一个echo中的一些错误（用点替换逗号）

Answer 2

PHP是服务器端语言 ，而JavaScript是客户端语言 。 如果您尝试在服务器端验证表单而不重新加载页面（并让JavaScript弹出警告），请查看AJAX 。

Answer 3

尝试这个

  if(!$mail->Send()) {
    echo "Error sending form! You are trying to send too large files. Their size is: ".$totalSize." MB";
        ?>
<script type="text/javascript">
alert("Error sending form! You are trying to send too large files. Their size is: <?php echo $totalSize;?> ");
</script>
<?php }