Date对象格式化函数代码

/* 
* 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])?|[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 ([content]) { 
return [content] in flags ? flags[[content]] : [content].slice(1, [content].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); 
};

var now = new Date(); 

now.format("m/dd/yy"); 
// Returns, e.g., 6/09/07 

// Can also be used as a standalone function 
dateFormat(now, "dddd, mmmm dS, yyyy, h:MM:ss TT"); 
// Saturday, June 9th, 2007, 5:46:21 PM 

// You can use one of several named masks 
now.format("isoDateTime"); 
// 2007-06-09T17:46:21 

// ...Or add your own 
dateFormat.masks.hammerTime = 'HH:MM! "Can\'t touch this!"'; 
now.format("hammerTime"); 
// 17:46! Can't touch this! 

// When using the standalone dateFormat function, 
// you can also provide the date as a string 
dateFormat("Jun 9 2007", "fullDate"); 
// Saturday, June 9, 2007 

// Note that if you don't include the mask argument, 
// dateFormat.masks.default is used 
now.format(); 
// Sat Jun 09 2007 17:46:21 

// And if you don't include the date argument, 
// the current date and time is used 
dateFormat(); 
// Sat Jun 09 2007 17:46:22 

// You can also skip the date argument (as long as your mask doesn't 
// contain any numbers), in which case the current date/time is used 
dateFormat("longTime"); 
// 5:46:22 PM EST 

// And finally, you can convert local time to UTC time. Either pass in 
// true as an additional argument (no argument skipping allowed in this case): 
dateFormat(now, "longTime", true); 
now.format("longTime", true); 
// Both lines return, e.g., 10:46:21 PM UTC 

// ...Or add the prefix "UTC:" to your mask. 
now.format("UTC:h:MM:ss TT Z"); 
// 10:46:21 PM UTC