代码部分：

var http = require("http"); //加载http模块

var cheerio = require("cheerio"); //加载cheerio模块

var url = "http://www.imooc.com/learn/348";

// 获取课程数据

function filterChapters(html){

var $ = cheerio.load(html);

var chapters = $(".chapter");

/*

要获取的数据的结构

[{

chapterTitle: "",

videos: [

title: "",

id: ""

]

}]

*/

var courseData = [];

chapters.each(function(item){

var chapter = $(this);

var chapterTitle = chapter.find("strong").text().trim();

var videos = chapter.find(".video").children("li");

var chapterData = {

chapterTitle: chapterTitle,

videos: []

};

videos.each(function(item){

var video = $(this).find(".video");

var videoTitle = video.text();

var id = String(video.attr("href")).split("video/")[1];

chapterData.videos.push({

title: videoTitle,

id: id

});

});

courseData.push(chapterData);

})

return courseData

};

// 写入获取到的课程数据

function printCourseInfo(courseData){

courseData.forEach(function(item) {

var chapterTitle = item.chapterTitle;

console.log(chapterTitle + "\n");

item.videos.forEach(function(video){

console.log(" 【 " + video.id + " 】 " + video.title + "\n");

});

});

};

// get方法发送请求

http.get(url, function(res){

var html = "";

res.on("data", function(data){

html += data;

});

res.on("end", function(){

var courseData = filterChapters(html);

printCourseInfo(courseData);

});

}).on("error", function(){ //监听错误处理

console.log("获取课程数据出错！");

});