轻松搞定javascript日期格式化问题

 Date.prototype.format = function(f){
             var d = this
             f = f || "yyyy-MM-dd hh:mm:ss"
             return f.replace(/[yMdhms]+/g, function(item){
                 switch (item) {
                     case "yyyy":
                         return d.getFullYear()
                         break
                     case "MM":
                         return +d.getMonth() + 1 < 10 ? "0" + (+d.getMonth() + 1) : +d.getMonth() + 1
                         break
                     case "dd":
                         return +d.getDate() < 10 ? "0" + d.getDate() : d.getDate()
                         break
                     case "hh":
                         return +d.getHours() < 10 ? "0" + d.getHours() : d.getHours()
                         break
                     case "mm":
                         return +d.getMinutes() < 10 ? "0" + d.getMinutes() : d.getMinutes()
                         break
                     case "ss":
                         return +d.getSeconds() < 10 ? "0" + d.getSeconds() : d.getSeconds()
                         break
                 }
             })
         }

         var d = new Date()
         console.log(d.format())
         console.log(d.format("yyyy/MM/dd"))