javascript Date format(js日期格式化)

Date.prototype.format = function (format) {   
                if (!format) {
                    format = "yyyy-MM-dd hh:mm:ss";
                }                       //如果不是这个格式强制转换
                var o = {
                    "M+": this.getMonth() + 1, 
                    "d+": this.getDate(),
                    "h+": this.getHours(),
                    "m+": this.getMinutes(),
                    "s+": this.getSeconds(),
                    "q+": Math.floor((this.getMonth() + 3) / 3),
                    "S": this.getMilliseconds()

                };
                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;
            };

调用方法：

var time1 = new Date().format("yyyy-MM-dd HH:mm:ss");     
  
var time2 = new Date().format("yyyy-MM-dd");