var user = function(age){
    // 变量age 是user对象的私有属性
    var age = age;
}
 
// user.age 是user对象的静态方法
user.age = function(){
    return this.age;
}
 
// 当我们将user对象实例化的时候
// zhangsan 无法使用 user 对象中
// 的 age方法
var zhangsan = new user(18);
 
// 实例中没有继承user对象的age方法
alert(!!zhangsan.age == false);

var user = function(name,age){
    // 公共变量
    this.name = name;
    this.age = age;
}
 
// 公共方法
user.prototype = {
    getInfo: function(){
        return "他的名字叫：" +this.name+ "，他的年龄是：" +this.age;
    }
}
 
// 当我们将user对象实例化的时候
var zhangsan = new user("zhangsan",18);
 
// getInfo() 就是user对象的公共方法 name\age 既user对象的公共变量
alert(zhangsan.getInfo() == "他的名字叫：zhangsan，他的年龄是：18");
alert(zhangsan.name == "zhangsan");
alert(zhangsan.age == 18);

var user = function(age){
    // age 是user对象的私有属性
    var age = age;
 
    // getAget 是user对象的私有方法
    function getAge(){
        return age;
    }
}
 
var zhangsan = new user(18);
 
// 实例中不包含user对象的age属性
// 及getAge方法;
alert(zhangsan.age == undefined);
alert(zhangsan.getAge == undefined);

var user = function(age){
    // age 是user对象的私有属性
    var age = age;
 
    // 创建一个特权方法用来获取
    // user 对象下的私有属性age
    this.getInfo = function(){
       return age;
    }
}
 
var zhangsan = new user(18);
alert(zhangsan.getInfo() == 18);

/*
 * Date Format 1.2.3
 * (c) 2007-2009 Steven Levithan
 * MIT license
 *
 * Includes enhancements by Scott Trenda
 * and Kris Kowal
 *
 * Accepts a date, a mask, or a date and a mask.
 * Returns a formatted version of the given date.
 * The date defaults to the current date/time.
 * The mask defaults to dateFormat.masks.default.
 */
 
var dateFormat = function () {
	var	token = /d{1,4}|m{1,4}|yy(?:yy)?|([HhMsTt])\1?|[LloSZ]|"[^"]*"|'[^']*'/g,
		timezone = /\b(?:[PMCEA][SDP]T|(?:Pacific|Mountain|Central|Eastern|Atlantic) (?:Standard|Daylight|Prevailing) Time|(?:GMT|UTC)(?:[-+]\d{4})?)\b/g,
		timezoneClip = /[^-+\dA-Z]/g,
		pad = function (val, len) {
			val = String(val);
			len = len || 2;
			while (val.length < len) val = "0" + val; 			return val; 		}; 	// Regexes and supporting functions are cached through closure 	return function (date, mask, utc) { 		var dF = dateFormat; 		// You can't provide utc if you skip other args (use the "UTC:" mask prefix) 		if (arguments.length == 1 && Object.prototype.toString.call(date) == "[object String]" && !/\d/.test(date)) { 			mask = date; 			date = undefined; 		} 		// Passing date through Date applies Date.parse, if necessary 		date = date ? new Date(date) : new Date; 		if (isNaN(date)) throw SyntaxError("invalid date"); 		mask = String(dF.masks[mask] || mask || dF.masks["default"]); 		// Allow setting the utc argument via the mask 		if (mask.slice(0, 4) == "UTC:") { 			mask = mask.slice(4); 			utc = true; 		} 		var	_ = utc ? "getUTC" : "get", 			d = date[_ + "Date"](), 			D = date[_ + "Day"](), 			m = date[_ + "Month"](), 			y = date[_ + "FullYear"](), 			H = date[_ + "Hours"](), 			M = date[_ + "Minutes"](), 			s = date[_ + "Seconds"](), 			L = date[_ + "Milliseconds"](), 			o = utc ? 0 : date.getTimezoneOffset(), 			flags = { 				d:    d, 				dd:   pad(d), 				ddd:  dF.i18n.dayNames[D], 				dddd: dF.i18n.dayNames[D + 7], 				m:    m + 1, 				mm:   pad(m + 1), 				mmm:  dF.i18n.monthNames[m], 				mmmm: dF.i18n.monthNames[m + 12], 				yy:   String(y).slice(2), 				yyyy: y, 				h:    H % 12 || 12, 				hh:   pad(H % 12 || 12), 				H:    H, 				HH:   pad(H), 				M:    M, 				MM:   pad(M), 				s:    s, 				ss:   pad(s), 				l:    pad(L, 3), 				L:    pad(L > 99 ? Math.round(L / 10) : L),
				t:    H < 12 ? "a"  : "p",
				tt:   H < 12 ? "am" : "pm",
				T:    H < 12 ? "A"  : "P",
				TT:   H < 12 ? "AM" : "PM", 				Z:    utc ? "UTC" : (String(date).match(timezone) || [""]).pop().replace(timezoneClip, ""), 				o:    (o > 0 ? "-" : "+") + pad(Math.floor(Math.abs(o) / 60) * 100 + Math.abs(o) % 60, 4),
				S:    ["th", "st", "nd", "rd"][d % 10 > 3 ? 0 : (d % 100 - d % 10 != 10) * d % 10]
			};
 
		return mask.replace(token, function ($0) {
			return $0 in flags ? flags[$0] : $0.slice(1, $0.length - 1);
		});
	};
}();
 
// Some common format strings
dateFormat.masks = {
	"default":      "ddd mmm dd yyyy HH:MM:ss",
	shortDate:      "m/d/yy",
	mediumDate:     "mmm d, yyyy",
	longDate:       "mmmm d, yyyy",
	fullDate:       "dddd, mmmm d, yyyy",
	shortTime:      "h:MM TT",
	mediumTime:     "h:MM:ss TT",
	longTime:       "h:MM:ss TT Z",
	isoDate:        "yyyy-mm-dd",
	isoTime:        "HH:MM:ss",
	isoDateTime:    "yyyy-mm-dd'T'HH:MM:ss",
	isoUtcDateTime: "UTC:yyyy-mm-dd'T'HH:MM:ss'Z'"
};
 
// Internationalization strings
dateFormat.i18n = {
	dayNames: [
		"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat",
		"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"
	],
	monthNames: [
		"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec",
		"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"
	]
};
 
// For convenience...
Date.prototype.format = function (mask, utc) {
	return dateFormat(this, mask, utc);
};