How can I append/add new property with same key name inside declared object ?

Here the code:

// Declared object

var myObject = {

    name : 'John',

    age  : 15,

};



// Array list of new property need to be add to myObject

var others = [

  { key : 'hobby', value: 'reading' },

  { key : 'hobby', value: 'writing' }

];

What i've been try so far:

ko.utils.arrayForEach(others, function(other) {

    myObject[other.key] = other.value;

});

and

ko.utils.arrayForEach(others, function(other) {

    var extendObject = new Object();

    extendObject[other.key] = other.value;



    $.extend(myObject, extendObject);

});

The result still both doesn't work either. It just replace existing property value

What I need is something like this:

myObject: { name: 'John', age: 15, hobby: 'reading', hobby: 'writing' }

Please note: I don't want to make it array : hobby: ['reading', 'writing']

UPDATE:

I was implement this for search functionality, code and details above is simplified version of the part I was stuck.

and here is the full code of what i've try to accomplish:

my views:

<form data-bind=submit: $root.getSearchData>

  <input name=date_start class=datepicker>



  <div class=checkbox>

    <label>

       <input type=checkbox name=user_id[] value=1> John

    </label>

    <label>

       <input type=checkbox name=user_id[] value=2> Michael

    </label>

  </div>

</form>

my viewmodels:

// Will contains new search property need to append to queryData

self.searchPropertyList = ko.observableArray();



// This function will fetch tasks from server

self.getTasksFromServer = function()

{

   // Query data

   var queryData = {

       sort : 'start',

       order: 'asc'

   };



   /**

    * When getSearchData function fill formData into searchPropertyList observable,

    * this function will get a notify and it will automatically loop through it 

    * and append new property to queryData.

    */

   ko.utils.arrayForEach(self.searchPropertyList(), function(opt)

   {

       queryData[opt.name] = opt.value;

   }



   $.ajax({

       url: 'api/tasks',

       type: 'json',

       data: queryData,

       success: function(data)

       {

       }

   });

}



// Returned form property as array into searchPropertyList observableArray 

// and notify getTaskFromServer function

// This is how formData may look like

// formData = [{ name: 'date_start', value: '2014-08-26' }, { name: 'user_id[]', value: 1 }, { name: 'user_id[]', value: 2 }]; 

self.getSearchData = function(form)

{

     var formData = $(form).serializeArray();



     self.searchPropertyList(formData);

}

So, ajax will request something like this:

api/tasks?sort=start&order=asc&date_start=2014-08-26&user_id[]=1&user_id[]=2

Someone, please help, Thanks :)