javascript类中未警告的jQuery最接近函数变为未定义的值

Question

I have a code that waste my few hours. Here jquery closest with class not working in html table and not passing value. I use html, javascript, jquery and php here. Can anyone rewrite the code freshly.

<script>
$(document).ready(function () {
    $(".senddata").on("click", function () {
        var subans = 
 $(this).closest(".datadivision").find("input[name='subans']").val();
        var data = 'subans=' + subans;
        $.ajax({
            type: "POST",
            url: "test.php",
            data: data,
            cache: false,
            success: function (html) {
                alert(html);
            }
        });
    });
    });
 </script>

  <table>
  <tr class="datadivision">
  <input type="hidden" name="subans" value="A" >
  <td class= "senddata">       
  <label><input type="radio" name="subans" value="something"> This is a 
  line</label>     
  </td> 
 </tr>
 </table>

 <?php
  if (isset($_POST['subans'])) {
    $subans = $_POST['subans'];
   if (!empty($subans)) {
    echo $subans;
    }
   }
   ?>

Answer 1

Assuming that you want the alert to show the value "A" , JavaScript is not the issue. The problem is that you are printing the whole page, even when the request is POST .

Instead, you should conditionally print the page only when the request is not POST, or when it does not contain subans property. Like this:

<?php
if (isset($_POST['subans'])) {
    $subans = $_POST['subans'];
    if (!empty($subans)) {
        echo $subans;
    }
} else {
    ?>
    <script src="https://code.jquery.com/jquery-3.3.1.js"></script>
    <script>
      $(document).ready(function () {
        $(".senddata").on("click", function () {
          console.log(this)
          var subans =
            $(this).closest(".datadivision").find("input[name='subans']").val();
          var data = 'subans=' + subans;
          $.ajax({
            type: "POST",
            url: "stack.php",
            data: data,
            cache: false,
            success: function (html) {
              alert(html);
            }
          });
        });
      });
    </script>

    <table>
        <tr class="datadivision">
            <input type="hidden" name="subans" value="A" >
            <td class= "senddata">
                <label><input type="radio" name="subans" value="something"> This is a
                    line</label>
            </td>
        </tr>
    </table>
<?php
}
?>