javascript字符串和日期怎么互转

stringToDate : function(dateStr,separator){

     if(!separator){

            separator="-";

     }

     var dateArr = dateStr.split(separator);

     var year = parseInt(dateArr[0]);

     var month;

     //处理月份为04这样的情况                        

     if(dateArr[1].indexOf("0") == 0){

         month = parseInt(dateArr[1].substring(1));

     }else{

          month = parseInt(dateArr[1]);

     }

     var day = parseInt(dateArr[2]);

     var date = new Date(year,month -1,day);

     return date;

 },