为什么JavaScript不设置隐藏字段的值

Question

我有一个PHP表单要提交，我正在尝试使用(香草(JavaScript来设置隐藏字段的值。由于某种原因，隐藏字段(deleteRowId(显示为空白。任何帮助都将不胜感激。

这是我的代码：

<?php
if (isset($transcribercertifications)) {
echo form_open('user/deletecertification/' . $tid, 'id="deleteCert"');
echo '<table>';
$count = 0;
if ($transcribercertifications) {
foreach ($transcribercertifications as $transcribercertification) {
echo '<tr><td>' . $transcribercertification . '</td>';
echo '<input type="hidden" name="certification[' . $count . ']" id="certification[' . $count . ']" value="' . $transcribercertification . '">';
echo '<input type="hidden" id="deleteRowId" name="deleteRowId" value="">';
echo '</td><td title="Delete certification"><button data-row-id="' . $count . '" id="deleteCert" onclick="deleteRow(' . $count . ');">X</button></td></tr>';
$count++;
}
}
echo '</table>';
echo form_close();
}
?>
<script type="text/javascript">
function deleteRow(rowCount) {
event.preventDefault()
alert('This will delete the certification. Are you sure ?');
alert(rowCount); // This value comes through correctly.
document.getElementById('deleteRowId').value = rowCount;
document.getElementById('deleteCert').submit();
}
</script>

调用函数时，deleteRowId始终为空。如果有另一种方法可以设置deleteRowId的值，以便函数知道要删除哪个证书，我也会对此感兴趣。

Answer 1

首先id="deleteRowId"必须是唯一的可以使用setAttribute方法

示例

<input type="hidden" value="111" id="uniqID1">
<input type="hidden" value="111" id="uniqID2">
<script>
let aaa = document.getElementById("uniqID1");
aaa.setAttribute('value',222);
console.log(aaa.value)
</script>

Answer 2

Id不能重复在foreach循环中用作id="deleteRowId"'$计数。"">id="deleteCert"'$计数。"">

foreach ($transcribercertifications as $transcribercertification) {
echo '<tr><td>' . $transcribercertification . '</td>';
echo '<input type="hidden" name="certification[' . $count . ']" id="certification[' . $count . ']" value="' . $transcribercertification . '">';
echo '<input type="hidden" id="deleteRowId"'.$count.'"" name="deleteRowId"'.$count.'"" value="">';
echo '</td><td title="Delete certification"><button data-row-id="' . $count . '" id="deleteCert"'.$count.'"" onclick="deleteRow(' . $count . ');">X</button></td></tr>';
$count++;
}

以及在JS函数中

getElementByID('deleteRowId'+rowCount).
getElementByID('deleteCert'+rowCount)