check atleast one checkbox is checked on form submission

Question

I have a form that consists of checkbox fields, now on form submission we should check whether atleast one checkbox is checked

html code

Answer 1

You shouldn't attach JavaScript event directly in the HTML, this is a really bad practice. Instead, because you use jQuery, you should use jQuery event handler :

$('#form_check').on('submit', function (e) {
  if ($("input[type=checkbox]:checked").length === 0) {
      e.preventDefault();
      alert('no way you submit it without checking a box');
      return false;
  }
});

(http://jsbin.com/IXeK/1/edit)

If you really want to use HTML onsubmit, even if it's bad (and you should feel bad just by thinking of it), the onsubmit should be:

• attached to the form
• should prevent the default event on submit
• return false

So it covers everything. Like here http://jsbin.com/IXeK/2/edit

function atleast_onecheckbox(e) {
  if ($("input[type=checkbox]:checked").length === 0) {
      e.preventDefault();
      alert('no way you submit it without checking a box');
      return false;
  }
}