14. Combination mode

var News = function() { this.children = [] this.element = null } News.prototype = { init: function() { throw new Error('initinit') }, add: function() { throw new Error('addadaddadad') }, getElement: function() { throw new Error('getelement') } } var container = function(id, parent) { News.call(this) this.id = id this.parent = parent this.init() } container.prototype = new News() container.prototype.init = function() { this.element = document.createElement('ul') this.element.id = this.id this.element.className = 'newContainer' } container.prototype.add = function(child) { this.children.push(child) this.element.appendChild(child.getElement()) return this } container.prototype.getElement = function() { return this.element } container.prototype.show = function() { this.parent.appendChild(this.element) } var Item = function(className) { News.call(this) this.className = className this.init() } Item.prototype = new News() Item.prototype.init = function() { this.element = document.createElement('li') this.element.className = this.className }  Item.prototype.add = function(child) { this.children.push(child) this.element.appendChild(child.getElement()) return this } Item.prototype.getElement = function() { return this.element } var new1 = new container('news', document.body) new1.add(new Item('normal'))Copy the code