-----------------------------------------------------------------cc = function(){alert(345)},pushStack = function() {    cc();},pushStack();//345//没加var的放在window对象中pushStack = function() {    cc();},cc = function(){alert(345)},pushStack();//345----------------------------------------------------------------pushStack = function() {    cc();//cc is not defined};pushStack();cc = function(){alert(345)};pushStack = function() {    cc();};pushStack();//345function cc(){alert(345)};----------------------------------------------------------------cc = function(){alert(345)};pushStack();//pushStack is not defined ,js解析器执行到这里的时候pushStack还是未定义pushStack = function() {    cc(); };cc = function(){alert(345)};pushStack();//345,js解析器执行到这里的时候pushStack已经定义了function pushStack() {    cc(); };

 

name = '2';a = function(){    alert(this.name);    alert(888);},o =　{    fn1 : function(){            a = function(){             //fn1执行的时候（fn1要执行，不执行是加不进去的）把a加到window里面去，把外部的a方法覆盖了                alert(this.name);//2  window                alert(this);//2                alert(666);            };            a();//666  a.call(window)            window.a();//666    }}o.fn1();window.a();// 2   666

 

name = '2';a = function(){    alert(this.name);    alert(888);},o =　{    fn1 : function(){            this.a = function(){
   //fn1执行，给o对象加了a方法                alert(this.name);                 alert(this);                alert(666);            };            a(); //2   888    a.call(window)   ，都是从window中找a()没有就报错            window.a(); //2  888    }}o.fn1();window.a();// 2   888 o.a();//666

name = '2';a = function(){    alert(this.name);    alert(888);},o =　{    fn1 : function(){            var a = function(){ //fn1函数执行，就有2个a方法，一个在fn1局部作用域，一个在window                alert(this.name);                 alert(this);                alert(666);            };            a(); //2  666  a.call(window)，查找局部作用域的a方法            window.a(); // 2  888    }}o.fn1();window.a();//  2   888

 

jQuery = function() {            alert(1);            return new jQuery.fn.init();        },        jQuery.fn = jQuery.prototype = {
   //fn是类的静态属性        //能够调用jQuery原型里（constructor()、pushStack()）方法的只能是jQuery对象或者init对象:$('div')。                constructor: jQuery,                init: function() {                },                //$('div').pushStack，this是$('div')，                pushStack: function() {                    alert(2);                    this.constructor();//1,  this是init对象或者jQuery对象$('div')，返回的是新的空init对象                    constructor();//constructor.call(window),调不了报错，                },        }        jQuery.fn.init.prototype = jQuery.fn;        var j = constructor();//window调用不了        $('div').pushStack();//1,2,1, $('div')是init对象可以调用pushStack()方法        o = {}        o.pushStack();//o.pushStack is not a function,能够调用pushStack方法是jQuery的对象后者init对象，        new jQuery.fn.init().pushStack();//2 1