Implement the format () function of the Date object in JavaScript

Implement the format () function of the Date object in JavaScript

Due to Web page display problems, it is often necessary to convert the date into a certain format, but the JavaScript scripting language is not provided to them officially. Programmers are very lazy. Let's write it by ourselves, expand it by yourself !!

 

/** * Author Joyce.Luo 11:57:35 prepared in 2015.02.10 * JavaScript language Methods: format(), based on the replace() method to realize * For example： *         new Date().format("yyyy-MM-dd HH:mm:ss"); *         new Date().format("yyyy-MM-dd"); * @param {} pattern the pattern describing the date and time format * @return {} returns a formatted string date */Date.prototype.format = function(pattern){    var o = {        "M+" : this.getMonth()+1,                 /*Month*/        "d+" : this.getDate(),                    /*Day*/        "h+" : this.getHours(),                   /*Hours*/        "m+" : this.getMinutes(),                 /*Minute*/         "s+" : this.getSeconds(),                 /*Seconds*/        "q+" : Math.floor((this.getMonth()+3)/3), /*Quarter*/        "S"  : this.getMilliseconds()             /*Millisecond*/    };    if (/(y+)/.test(pattern))        pattern = pattern.replace(RegExp.$1, (this.getFullYear() + "").substr(4 - RegExp.$1.length));    for (var k in o)        if (new RegExp("(" + k + ")").test(pattern))            pattern = pattern.replace(RegExp.$1, (RegExp.$1.length == 1) ? (o[k]) : (("00" + o[k]).substr(("" + o[k]).length)));    return pattern;}

In fact, this can be optimized, but I will not change the time. If you are interested, you can rewrite it in the comments.