W3School TIY Editor
W3School 在线教程
改变方向
暗黑模式
运行代码
<!DOCTYPE html> <html> <body> <p>输入您的年龄并点击按钮：</p> <input id="age" value="18"> <button onclick="myFunction()">试一试</button> <p id="demo"></p> <script> function myFunction() { var age, voteable; age = document.getElementById("age").value; voteable = (age < 18) ? "Too young":"Old enough"; document.getElementById("demo").innerHTML = voteable + " to vote."; } </script> </body> </html>