这一节主要讲了动态查询

此节主要讲了M 和D 的区别M是直接去找系统自带的Model基类D是直接去找你创建的UserModel类可以再模型中自定义字段和字段属性   可以过滤字段

查询$conditon['id']=1;var_dump($user->$conditon($conditon)->select) 

1.typeof 操作符2.undefined 未定义3.boolen4.object5.string6.number 

var $ = function () { return new Base();}function Base() {//创建一个数组，来保存获取的节点和节点数组 this.elements = []; //获取ID节点 this.getId = function (id) { this.elements.push(document.getElementById(id)); return this; }; //获取元素节点 this.getTagName = function (tag) { var tags = document.getElementsByTagName(tag); for (var i = 0; i < tags.length; i ++) { this.elements.push(tags[i]); } return this; };}Base.prototype.css = function (attr, value) { for (var i = 0; i < this.elements.length; i ++) { this.elements[i].style[attr] = value; } return this;}Base.prototype.html = function (str) { for (var i = 0; i < this.elements.length; i ++) { this.elements[i].innerHTML = str; } return this;}Base.prototype.click = function (fn) { for (var i = 0; i < this.elements.length; i ++) { this.elements[i].onclick = fn; } return this;}