01.阅读JQUERY源码——定义函数

(function(window,undefined){
var 
    rootjQuery,
    readyList,
    core_strundefined =typeof undefined，
    location =window.location,
    document =window.document,
    docElem =window.documentElement,
    _jQuery =window.jQuery,
    _$ = window.$,

    class2type = {},
    //无用了
    core_deletedIds = [],
    core_version = "2.0.3",
    //Save a reference to some core metheds
    core_concat =core_deletedIds.concat,
    core_push=core_deletedIds.push,
    core_slice =core_deletedIds.slice,
    core_indexOf =core_deletedIds.indexOf,
    core_toString = class2type.hasOwnProperty,
    core_trim =core_version.trim,
    //定义jQ函数
    jQuery = function(selector,context){
        return new jQuery.fn.init(selector,context,rootjQuery);
    }，
    

    //正则 暂缺

})(window)

/*————————————解析————————————————————————————*/
/*传window*/
1/速度更快
2/传参e取代window(压缩版)
/*传undefined*/
1/防止undefined被修改


/*严格模式下需要规范，否则会报错*/
"use strict"

/*不充分判断(IE9以下)*/
window.a == undefined
/*全兼容判断*/
typeof window.a == undefined

/*jQuery的对象设计方式*/
jQuery.fn=jQuery.prototype;
function jQuery(){
    return new jQuery.prototype.init();
}
jQuery.prototype.init =function(){}
jQuery.prototype.css =function(){}
jQuery.prototype.init.prototype = jQuery.prototype;
jQuery().css();
/*———————————————————————————————————————————————*/