如何从javasccript中的对象列表中删除重复项

 $(".search").keyup(function(){
     var val = this.value;

        $.ajax({
        type: "POST",
        url:  "search?entered=" + val,
        beforeSend: function(){    
            $(".search").css("background","#FFF");
        },
        success: function(data){
            for (var i = 0; i < data.length; i++) {
                $(".suggesstions").append("<ul>"+data[i]["category"]+" "+data[i]["productTitle"]+"</ul>");
             }

        }

        });

    });
 $(".search").keyup(function(){
     var val =