fmpq.com
源代码：
点击运行
<!DOCTYPE html> <html> <body> E-mail: <input type="email" id="myEmail"> <p>点击按钮设置 email 字段的长度。</p> <button onclick="myFunction()">点我</button> <script> function myFunction() { document.getElementById("myEmail").size = "50"; } </script> </body> </html>
运行结果