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> <input type="number" id="myNumber" placeholder="Quantity"> <p>点击按钮修改 number 字段的提示信息。</p> <button onclick="myFunction()">点我</button> <p id="demo"></p> <script> function myFunction() { document.getElementById("myNumber").placeholder = "Amount"; } </script> </body> </html>
运行结果