object passed as reference

Ive been trying to troubleshoot a function to return a load of values containing in a data attribute, but when the element is passed to the function the object is empty, I dont understand what Im doing wrong.

My function is:-

function convert2Arr(objThis) {
	debugger;
  var objArr = {};
  $.each(objThis.data("jsonfields").split(" "), function(key, value) {
    if ($(value).attr("type") === "checkbox") {
      if ($(value).is(':checked')) {
        objArr[value] = true;
      } else {
        objArr[value] = false;
      }
    } else if ($(value).attr("type") === "radio") {
      if(typeof $(value + ":checked").val() != 'undefined') {
        objArr[value] = $(value + ":checked").val();
        alert("Defined - " + $(value + ":checked").val());
      }
    } else {
      objArr[value] = $(value).val();
    }
  });
}

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Im assuming I can call this by:-

convert2Arr($("#btnLogin"))

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The idea is to list all the inputs in a data attribute in a element and return them all in an array. For example:-

<button id="btnLogin" data-jsonFields="#txtUsername #txtPassword #txtArea #txtDrop #radioGender #cbox1 #cbox2 #cbox3">Login</button>

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To show what Im trying to do, Ive got it on a jsfiddle:-
https://jsfiddle.net/o62rxyqc/

Any advice of what Im doing wrong?

Thanks in advance