SOURCE

var Folder  = function(name){
			this.name = name;
			this.files = [];
		}

		Folder.prototype.add = function(file){
			this.files.push(file)
		}

		Folder.prototype.scan = function(){
			console.log("开始扫描文件夹:" + this.name);
			for(var i=0,file,files = this.files;file = files[i++];){
				file.scan()
			}
		}
		// file
		var File = function(name){
			this.name = name;
		}
		File.prototype.add = function(){
			throw new Error('文件下面不能再添加文件')
		}
		File.prototype.scan = function(){
			console.log("开始扫描文件:" + this.name)
		}
		var folder = new Folder('学习资料');
		var folder1 = new Folder('JavaScript');
		var folder2 = new Folder('JQuery');

		var file1 = new File('JavaScript设计模式与开发实践');
		var file2 = new File('精通JQuery');
		var file3 = new File('重构与模式');

		folder1.add(file1);
		folder2.add(file2);
		folder.add(folder1)
		folder.add(folder2)
		folder.add(file3)

		var folder3 = new Folder('Node.js');
		var file4 = new File('深入浅出Node.js');
		folder3.add(file4);

		var file5 = new File('JavaScript语言精髓与编程实践');
		folder.add(folder3);
		folder.add(file5);

		folder.scan()