How to sum value of checked changed checkbox jquery?

http://stackoverflow.com/a/32022458/1144203

HTML

<form method="post">
  <fieldset>
    <legend>Menu</legend>
    <input type="checkbox" id="checkall" />Check All<br />
    <input type="checkbox" name="opt" id="candy" value="2" />Candy<br />
    <input type="checkbox" name="opt" id="food" value="€ 3" />Food<br />
    <input type="checkbox" name="opt" id="water" value="6.99" />Water<br />
  </fieldset>
</form>

JavaScript

(function($){    
  $("#checkall").change(function() {
    toggleCheckAll(this.checked)
    totalCount = calculateAll()
    alert(totalCount);
  });    
    
  $("input[name='opt']").change(function() {
      totalCount = calculateAll()
      alert(totalCount);
  });
    
  function toggleCheckAll(checked){
    $("input[name='opt']").prop('checked', checked)
  }
    
  function calculateAll(){
    count = 0;
    $("input[name='opt']").each(function(index, checkbox){
      if(checkbox.checked)
        count += parseInt(checkbox.value)
    })
    return count;  
  }
})(jQuery);