Check a value Exist in Array in Jquerry

Check Value in Array / return true false
var found = $.inArray(value, Array) > -1;

Removing Duplicates and push into a new Array.
var ResArray =["anil", "Kumar","anil"];
 $.each($.unique(ResArray), function(i, el){
                    uniqueNames.push(el);
                });
Out Put:
uniqueNames=["Anil", "Kumar"];

Pick The Extra users After Comparing 2 Arrays:

var PickedUsers=["1","2"];
var uniqueNames=["2"];
var extraUsers=[];
jQuery.grep(PickedUsers, function (el) {
                    if (jQuery.inArray(el, uniqueNames) == -1)
                        extraUsers.push(el);

                });
Out Put:

extraUsers=["1"];