源代码
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>享学课堂</title> </head> <body> <h1>JavaScript Math.PI</h1> <p>Math.PI 返回圆周长与其直径之比:</p> <p id="demo"></p> <script> document.getElementById("demo").innerHTML = Math.PI; </script> </body> </html>
运行结果