通过Javascript将HTML下拉菜单值传递给HTML输入

<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>

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

const dropdown = document.getElementById("dropdown");
const input = document.getElementById("input");

dropdown.addEventListener("change", function() {
  input.value = dropdown.value;
});