I thought this was supposed to be easy. There are a lot of answers on here about unchecking checkboxes using jQuery but when I try them they don't seem to work. I want to uncheck them as part of my function for resetting the form.

I have a loop and I create checkboxes inside it:
<input type=checkbox name=is_chosen[] value={{ $sample->id }} class=flat>

Here is the my code for unchecking checkboxes (not all checkboxes are checked initially):

$('input:checkbox').each(function () {

  if(this.checked) {

    $(this).attr('checked', false);

  }

});

I have also tried replacing attr with prop. I have also tried using just $(input:checkbox).prop('checked', false);. I have tried others more but they don't work. What am I missing?