Onclick 值显示在另一个输出中

Question

当我单击下拉列表中的值时遇到问题。它应该自动显示权重（总计）。有人可以帮助我如何将默认情况下从标记分配下拉表单中的值自动调用为权重（总计）。标记分配代码：<div class="form-row">  <label>Marks Allocation (%):</label>  <select name="percentage" class="form-control" oninput="this.className = ''">    <?php     $sql = mysqli_query($connection,"SELECT * FROM continous_assess");     while ($row=mysqli_fetch_array($sql))    { ?>    <option value="">      <?php echo $row['percentage']; ?>    </option>    <?php     }    ?>  </select></div>权重代码：<div class="form-group">  <label>Weightage</label>  <input type="number" name="first" class="prc" />  <input type="number" name="second" class="prc" />  <input type="number" name="third" class="prc" />  <input type="number" name="fourth" class="prc" />  <input type="number" name="fifth" class="prc" />  <label>Total</label>  <output value="<?php echo $row['percentage'];?>"></output></div>

Answer 1

这应该对您有所帮助；

<script type="text/javascript">

function updateVal() {

    // Get value

    var val = document.getElementById("percentage").value;

    // Set value

    document.getElementById("exampleInput").value = val;    

}

</script>

<select name="percentage" id="percentage" onchange="updateVal()">

    <option value="">- Select something -</option>

    <option value="example1">Example 1</option>

    <option value="example2">Example 2</option>

    <option value="example3">Example 3</option>

</select>

<input type="text" name="exampleInput" id="exampleInput">