AngularJS - Factory to hold an Array

How can I update this code to  hold an array of   values.

I want to hold FIELDNAME  and the VALUE

I want to set / add to the list by doing the following - add a value to the array/list.
       

   userFilters.setData(' lastname', 'smith');
   userFilters.setData(' firstname', 'bob');
   userFilters.setData(' Mi', 'D');

And have the object hold an Array of

'lastname','smith'
'firstname','bob'
'mi','D'





App.factory('userFilters', [function () {

    var data = {};

    var getData = function (field) {
        return data[field];
    };

    var setData = function (field, value) {
        data[field] = value;
    };

    return {
        getData: getData,
        setData: setData
    }
}]);