2.2 关于函数
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="refresh" content="10">
<title>JavaScript</title>
<script>
document.write("你好");
function say() {
document.write("hello");
}
</script>
</head>
<body>
<p>JavaScript</p>
<script>
say();
</script>
</body>
</html>