Formatting of date objects in JavaScript

Many languages have date-formatted functions, but JavaScript does not provide a similar approach.
The following code was found in one of the previous posts, and it was very concise and reserved.

/** * Formatting of the time object;*/Date.prototype.format=function(format) {/*example var d=new Date ();       D.format ("Yyyy-mm-dd hh:mm:ss"); Result: "2014-01-02 12:34:56"*/    varo = {        "m+": This. GetMonth () + 1,//Month"D+": This. GetDate (),//Day"H +": This. GetHours (),//hours"m+": This. getminutes (),//minutes"S+": This. getseconds (),//seconds"q+": Math.floor (( This. GetMonth () + 3)/3),//Quarterly"S": This. Getmilliseconds ()//milliseconds    }    if(/(y+)/. Test (format)) {Format= Format.replace (Regexp.$1, ( This. getFullYear () + "")//years. substr (4-regexp.$1. length)); }     for(varKincho) {if(NewRegExp ("(" + K + ")"). Test (format)) {format= Format.replace (regexp.$1, regexp.$1.length = = 1?)O[k]: ("XX" + o[k]). substr ("" +O[k]) (length)); }    }    returnformat;}