51help TIY
码：
<!DOCTYPE html> <html> <body> <h1>My First Web Page</h1> <p id="demo">A Paragraph.</p> <button type="button" onclick="myFunction()">点击这里</button> <script> function myFunction() { document.getElementById("demo").innerHTML="My First JavaScript Function"; } </script> </body> </html>
查看结果: