4 ways to asynchronously load js, the review begins.
Option 1: $(document).ready
<!DOCTYPE html>
<html>
<head>
<script src="http://common.cnblogs.com/script/jquery.js" type="text/javascript"></script>
<script type="text/javascript">
$(document).ready(function() {
alert("加载完成！");
});
</script>
</head>
<body>
<img src="http://images.cnitblog.com/i/121863/201405/222202573569862.jpg" />
</body>
</html>
Comments:
1. Need to quote jquery
2. Compatible with all browsers.
Option 2:
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
