How do I count how many checkboxes are selected on a page with jQuery

Question

I want to count how many checkboxes on my page are selected using jQuery. I\'ve written the following code:

      var numberOfCheckboxesSelected = 0;
               


        

Answer 1

The first argument passed to the callback in each is the index, not the element. You should use this or a second argument:

$(':checkbox').each(function(idx, checkbox) {
      if (checkbox.attr('checked'))
          numberOfCheckboxesSelected++;
});

Moreover, the easier way to do this is to select only the checked elements with the :checked selector and then check the selection's length property:

var numberOfCheckboxesSelected = $('input:checkbox:checked').length;