fmpq.com
源代码：
点击运行
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>Fmpq教程(fmpq.com)</title> </head> <body> <form action="form_action.asp"> 主页: <input type="url" id="myURL" name="website" required> <input type="submit"> </form> <p>点击 "点我" 按钮查看在表单提交前URL字段是否为必填字段。</p> <button onclick="myFunction()">点我</button> <p id="demo"></p> <script> function myFunction() { var x = document.getElementById("myURL").required; document.getElementById("demo").innerHTML = x; } </script> </body> </html>
运行结果