W3School TIY Editor
W3School 在线教程
改变方向
暗黑模式
运行代码
<!DOCTYPE html> <html> <body> <form action="/demo/htmldom/action_page.php"> 电子邮件：<input type="email" id="myEmail" name="usremail" required> <input type="submit"> </form> <p>请单击“试一试”按钮，了解是否必须在提交表格前填写电子邮件字段。</p> <button onclick="myFunction()">试一试</button> <p id="demo"></p> <script> function myFunction() { var x = document.getElementById("myEmail").required; document.getElementById("demo").innerHTML = x; } </script> </body> </html>