title: How to check if all checkboxes are unchecked
body: <p>I am trying to make a function to check if all checkboxes are unchecked. I have a similar function for text boxes. As I have not worked with checkboxes much before, I'm not sure how to adapt it except for changing <code>input[type=text]</code> to <code>input[type=checkbox]</code>.</p>
  
  <p>Can anyone help me out? Thanks.  </p>
  
  <pre><code>var textinputs = document.querySelectorAll('input[type=text]'); 
  var empty = [].filter.call( textinputs, function( el ) {
       return !el.value
  });
  
      if (textinputs.length == empty.length) {
          alert("None filled");
          return false;
  }
  </code></pre>