通过dropdownlist填充表

<select id="dropdown">
  <option value="option1">选项1</option>
  <option value="option2">选项2</option>
  <option value="option3">选项3</option>
</select>

<table id="table">
  <thead>
    <tr>
      <th>列1</th>
      <th>列2</th>
      <th>列3</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td id="cell1"></td>
      <td id="cell2"></td>
      <td id="cell3"></td>
    </tr>
  </tbody>
</table>

// 获取dropdownlist和table的元素
var dropdown = document.getElementById("dropdown");
var table = document.getElementById("table");
var cell1 = document.getElementById("cell1");
var cell2 = document.getElementById("cell2");
var cell3 = document.getElementById("cell3");

// 监听dropdownlist的选择事件
dropdown.addEventListener("change", function() {
  // 根据选择的选项填充表格
  var selectedOption = dropdown.value;
  if (selectedOption === "option1") {
    cell1.textContent = "选项1的值";
    cell2.textContent = "选项1的值";
    cell3.textContent = "选项1的值";
  } else if (selectedOption === "option2") {
    cell1.textContent = "选项2的值";
    cell2.textContent = "选项2的值";
    cell3.textContent = "选项2的值";
  } else if (selectedOption === "option3") {
    cell1.textContent = "选项3的值";
    cell2.textContent = "选项3的值";
    cell3.textContent = "选项3的值";
  }
});