JavaScript Date Format Function performance comparison

Log functionality is needed in recently developed software, and one of the important features is the display of dates and times. So a search on the Internet, search to a large number of date format functions, but compared to the next, the sense of the code is not elegant, and performance is not to force.

Some of the code on the line was evaluated and the results were as follows:

The test code is as follows, and the Format function is evaluated 500,000 times, respectively:

The code is as follows	Copy Code
var start = new Date (). GetTime (); var date = new Date (); for (var i = 0;i<500000;i++) { DATE.FORMAT1 (' Yyyy-mm-dd hh:mm:ss '); } Console.log (New Date (). GetTime ()-start);

Function 1:

The code is as follows

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An extension to date that converts date to a string of the specified format Months (m), days (d), hours (h), minutes (m), seconds (s), quarter (q) can be used with 1-2 placeholders, Year (y) you can use 1-4 placeholders, milliseconds (s) to use only 1 placeholders (1-3-digit digits) Example: (New Date ()). Format ("Yyyy-mm-dd hh:mm:ss. S ") ==> 2006-07-02 08:09:04.423 (New Date ()). Format ("yyyy-m-d h:m:s.s") ==> 2006-7-2 8:9:4.18 DATE.PROTOTYPE.FORMAT1 = function (FMT) {//author:meizz var o = { "m+": This.getmonth () + 1,//month "D+": this.getdate (),//day "h+": this.gethours (),//hour "m+": this.getminutes (),//min "S+": This.getseconds (),//sec "q+": Math.floor (This.getmonth () + 3)/3),//Quarter "S": this.getmilliseconds ()//MS }; if (/(y+)/.test (FMT)) FMT = Fmt.replace (regexp.$1, (this.getfullyear () + ""). substr (4-regexp.$1.length)); For (var k in O) if (new RegExp ("+ K +") "). Test (FMT)) FMT = Fmt.replace (regexp.$1, (regexp.$1.length = 1)? (O[k]): (("+ o[k]"). substr (("" + o[k). length)); return FMT; }

Tested three times:

Score 1:6,657 milliseconds

Score 2:6,739 milliseconds

Score 3:6,747 milliseconds

Average: 6714 ms

Function 2:

The code is as follows

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/** * Extension of date to convert date to String * month (m), Day (d), 12 hours (h), 24 hours (h), minutes (M), seconds (s), Week (E), quarter (q) in the specified format can use 1-2 placeholder * year (y) can use 1-4 placeholders, milliseconds (S) can only use 1 placeholders (1-3 digits) * Eg: * (new Date ()). Pattern ("Yyyy-mm-dd hh:mm:ss. S ") ==> 2006-07-02 08:09:04.423 * (New Date ()). Pattern ("Yyyy-mm-dd E HH:mm:ss") ==> 2009-03-10 II 20:09:04 * (New Date ()). Pattern ("Yyyy-mm-dd EE hh:mm:ss") ==> 2009-03-10 Tuesday 08:09:04 * (New Date ()). Pattern ("Yyyy-mm-dd EEE hh:mm:ss") ==> 2009-03-10 Tuesday 08:09:04 * (New Date ()). Pattern ("yyyy-m-d h:m:s.s") ==> 2006-7-2 8:9:4.18 */ Date.prototype.format2=function (FMT) { var o = { "m+": This.getmonth () +1,//month "D+": this.getdate (),//day "h+": this.gethours ()%12 = 0? 12:this.gethours ()%12,//hour "h+": this.gethours (),//hour "m+": this.getminutes (),//min "S+": This.getseconds (),//sec "q+": Math.floor (This.getmonth () +3)/3),//Quarter "S": this.getmilliseconds ()//MS }; var week = { "0": "/u65e5", "1": "/u4e00", "2": "/u4e8c", "3": "/u4e09", "4": "/u56db", "5": "/u4e94", "6": "/U516D" }; if (/(y+)/.test (FMT)) { Fmt=fmt.replace (Regexp.$1, (this.getfullyear () + ""). substr (4-regexp.$1.length)); } if (/(e+)/.test (FMT)) { Fmt=fmt.replace (regexp.$1, (regexp.$1.length>1)? (regexp.$1.length>2?) "/u661f/u671f": "/u5468"): "") +week[this.getday () + ""]); } For (var k in O) { if (new RegExp ("+ K +") "). Test (FMT)) { FMT = Fmt.replace (regexp.$1, (regexp.$1.length==1)? (O[k]): (("+ o[k]"). substr (("" + o[k). length)); } } return FMT; }

Tested three times:

Score 1:7,334 milliseconds

Score 2:7,497 milliseconds

Score 3:7,498 milliseconds

Average: 7443 ms

In the spirit of perfectionism, I have built a better wheel, sharing the necessary students, the code is as follows:

The code is as follows

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/** * The date is formatted, * @param date on which date is to be formatted * Pattern string Formatted @param format * The supported pattern letters are: * Y: Year, * M: Months of the Year (1-12), * D: Days of the Month (1-31), * H: Hours (0-23), * M: Min (0-59), * S: Seconds (0-59), * S: Millisecond (0-999), * Q: Quarterly (1-4) * @return String * @author yanis.wang@gmail.com */ function DateFormat (date, format) { if (format = = = undefined) { format = date; Date = new Date (); } var map = { "M": Date.getmonth () + 1,//month "D": date.getdate (),//day "H": date.gethours (),//hour "M": date.getminutes (),//min "S": Date.getseconds (),//sec "Q": Math.floor (Date.getmonth () + 3)/3),//Quarter "S": date.getmilliseconds ()//MS }; Format = Format.replace (/[YMDHMSQS]) +/g, function (all, t) { var v = map[t]; if (v!== undefined) { if (All.length > 1) { v = ' 0 ' + V; v = v.substr (v.length-2); } return v; } else if (t = = = ' Y ') { Return (Date.getfullyear () + "). substr (4-all.length); } return all; }); return format; } How to use: DateFormat (' Yyyy-mm-dd hh:mm:ss '); DateFormat (New Date (), ' yyyy-mm-dd hh:mm:ss '); Tested three times: Score 1:2,903 milliseconds Score 2:2,900 milliseconds Score 3:2,896 milliseconds Average: 2899 ms

The modified function increases the overall performance significantly, from 6714 milliseconds to 2899 milliseconds, reduced by 3815 milliseconds, overall to the original 43% time, performance increased by more than one times. And from the prototype injection mode to static function, more elegant and generous.