javaScript在表单提交时获取表单数据的示例代码

<form id="myForm">
  <input type="text" name="username" value="JohnDoe" />
  <input type="email" name="email" value="john@example.com" />
  <input type="password" name="password" value="12345" />
  <button type="submit">Submit</button>
</form>
<script>
  document.getElementById('myForm').addEventListener('submit', function (event) {
    event.preventDefault(); // 阻止默认表单提交行为
    // 获取表单数据
    const formData = new FormData(this);
    // 遍历表单数据
    for (let [key, value] of formData.entries()) {
      console.log(`${key}: ${value}`);
    }
    // 如果需要转换为 JSON 对象
    const data = Object.fromEntries(formData.entries());
    console.log(data);
  });
</script>

<form id="myForm">
  <input type="text" name="username" value="JohnDoe" />
  <input type="email" name="email" value="john@example.com" />
  <input type="password" name="password" value="12345" />
  <button type="submit">Submit</button>
</form>
<script>
  document.getElementById('myForm').addEventListener('submit', function (event) {
    event.preventDefault();
    const form = event.target;
    const formData = {};
    // 遍历表单元素
    Array.from(form.elements).forEach((element) => {
      if (element.name) {
        formData[element.name] = element.value; // 获取每个字段的值
      }
    });
    console.log(formData);
  });
</script>

<form id="myForm">
  <input type="text" id="username" name="username" value="JohnDoe" />
  <input type="email" id="email" name="email" value="john@example.com" />
  <button type="submit">Submit</button>
</form>
<script>
  document.getElementById('myForm').addEventListener('submit', function (event) {
    event.preventDefault();
    // 获取单个字段值
    const username = document.querySelector('#username').value;
    const email = document.querySelector('#email').value;
    console.log(`Username: ${username}`);
    console.log(`Email: ${email}`);
  });
</script>

<form id="myForm">
  <input type="text" name="username" value="JohnDoe" />
  <input type="email" name="email" value="john@example.com" />
  <button type="submit">Submit</button>
</form>
<script>
  document.getElementById('myForm').addEventListener('submit', function (event) {
    event.preventDefault();
    const formData = new FormData(this);
    // 转换为 URL 查询参数
    const queryString = new URLSearchParams(formData).toString();
    console.log(queryString); // username=JohnDoe&email=john%40example.com
  });
</script>

<form id="myForm">
  <input type="text" name="username" value="JohnDoe" />
  <input type="email" name="email" value="john@example.com" />
  <button type="submit">Submit</button>
</form>
<script>
  document.getElementById('myForm').addEventListener('submit', function (event) {
    event.preventDefault();
    const formData = new FormData(this);
    // 提交表单数据到服务器
    fetch('/submit', {
      method: 'POST',
      body: formData,
    })
      .then((response) => response.json())
      .then((data) => console.log(data))
      .catch((error) => console.error('Error:', error));
  });
</script>