根据onclick表值预先选择下拉选项，然后导航到另一个页面

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

<button onclick="navigateToAnotherPage()">导航</button>

function navigateToAnotherPage() {
  var selectElement = document.getElementById("mySelect");
  var selectedOption = selectElement.value;

  if (selectedOption === "option1") {
    window.location.href = "page1.html"; // 导航到页面1
  } else if (selectedOption === "option2") {
    window.location.href = "page2.html"; // 导航到页面2
  } else if (selectedOption === "option3") {
    window.location.href = "page3.html"; // 导航到页面3
  }
}