JS自定义.format方法格式化时间

Date.prototype.format = function(format){ 
	var o = { 
	"M+" : this.getMonth()+1, //month 
	"d+" : this.getDate(), //day 
	"h+" : this.getHours(), //hour 
	"m+" : this.getMinutes(), //minute 
	"s+" : this.getSeconds(), //second 
	"q+" : Math.floor((this.getMonth()+3)/3), //quarter 
	"S" : this.getMilliseconds() //millisecond 
	};

	if(/(y+)/.test(format)) { 
	format = format.replace(RegExp.$1, (this.getFullYear()+"").substr(4 - RegExp.$1.length)); 
	} 

	for(var k in o) { 
	if(new RegExp("("+ k +")").test(format)) { 
	format = format.replace(RegExp.$1, RegExp.$1.length==1 ? o[k] : ("00"+ o[k]).substr((""+ o[k]).length)); 
	} 
	} 
	return format; 
	} ;