demo_cr.js

var http = require('http');
var cheerio = require('cheerio');
var url = 'http://www.imooc.com/learn/348';

function filterChapters(html) {
    var $ = cheerio.load(html);
    var chapters = $('.chapter');

    var courseData = [];
    chapters.each(function(item) {
        var chapter = $(this);
        var chapterTitle = chapter.find('strong').text();
        var videos = chapter.find('.video').children('li');
        var chapterData = {
            chapterTitle: chapterTitle,
            video: []
        };
        videos.each(function(item) {
            var video = $(this).find('.J-media-item');
            var videoTitle = video.text();
            var id = video.attr('href').split('video/')[1];
            chapterData.video.push({
                title: videoTitle,
                id: id
            });
        });
        //console.log(chapterData.video);
        courseData.push(chapterData);
    });
    return courseData;
}

function printCourseInfo(courseData) {
    courseData.forEach(function(item) {
        var chapterTitle = item.chapterTitle;
        console.log(chapterTitle + '\n');

        item.video.forEach(function(video) {
            console.log('【' + video.id + '】' + video.title + '\n');
        });
    });

}

http.get(url, function(res) {
    var html = '';
    res.on('data', function(data) {
        html += data;
    });

    res.on('end', function() {
        var courseData = filterChapters(html);
        //console.log(courseData.video);
        printCourseInfo(courseData);
    }).on('error', function() {
        console.log('获取课程数据出错');
    });
});