搜索重复值并从javascript对象中删除？

Question

好的，我有以下内容：

var alldatesdump = booking.getalldates();

var alldatesdumparray = $.map(booking.getalldates(), function(value, index) {
    var splitstring
    var dropdates = new Date(value.date);
    var dropdate = dropdates.getDate();
    var month=new Array();
month[0]="January";
month[1]="February";
month[2]="March";
month[3]="April";
month[4]="May";
month[5]="June";
month[6]="July";
month[7]="August";
month[8]="September";
month[9]="October";
month[10]="November";
month[11]="December";
    var dropmonth = month[dropdates.getMonth()];
    var dropyear = dropdates.getFullYear();
console.log(dropmonth + "-" + dropyear);

    return [value];
});

输出以下内容：

October-2014 
October-2014 
October-2014 
November-2014 
November-2014 
November-2014 

我如何阻止重复值，每月只放一次.... 克里斯