How to create json by JavaScript for loop?

I have array of select tag.

<select id='uniqueID' name="status">
      <option value="1">Present</option>
      <option value="2">Absent</option>
 </select>

and I want to create a json object having two fields 'uniqueIDofSelect and optionValue' in JavaScript.

I use getElementsByName("status") and I iterate on it.

EDIT

I need out put like

[{"selectID":2,"OptionValue":"2"},
{"selectID":4,"optionvalue":"1"}]

and so on...

From what I understand of your request, this should work:

<script>
//  var status  = document.getElementsByID("uniqueID"); // this works too
var status  = document.getElementsByName("status")[0];
var jsonArr = [];

for (var i = 0; i < status.options.length; i++) {
    jsonArr.push({
        id: status.options[i].text,
        optionValue: status.options[i].value
    });
}
</script>

var sels = //Here is your array of SELECTs
var json = { };

for(var i = 0, l = sels.length; i < l; i++) {
  json[sels[i].id] = sels[i].value;
}