防止表单的值在onclick事件后被重置，并将用户的输入保存在会话存储中

<form id="myForm">
  <input type="text" id="inputField" />
  <button onclick="saveInput()">保存</button>
</form>

function saveInput() {
  event.preventDefault(); // 阻止表单的默认提交行为

  var inputField = document.getElementById("inputField");
  var userInput = inputField.value;

  sessionStorage.setItem("userInput", userInput);
}

window.onload = function() {
  var userInput = sessionStorage.getItem("userInput");

  if (userInput) {
    var inputField = document.getElementById("inputField");
    inputField.value = userInput;
  }
};