编辑下面的代码:【加编码】
<html> <body> <p>Click the button to demonstrate line-breaks in a popup box.</p> <button onclick="myFunction()">Try it</button> <p id="demo"></p> <script> function myFunction() { alert("Hello\nHow are you?"); } </script> </body> </html>
结果: 【此窗口】 帮助?
Try it Yourself - © 自强学堂