Loop through several check boxes and update inputs on results

I have several check boxes that I need to post the value of when a form is submitted. There is 4 at the moment and could be more so I was thinking of instead of adding individual functions is it possible to loop through them all and update respected fields in one go. I have seen a similar thing with form population with google maps but not quite the same. So I have a input like so:

function myCheck() {
    var checkBox = document.getElementById("email_alerts");
    if (checkBox.checked == true){
        document.getElementById('form_email_alerts').value = 'YES'
    } else {
        document.getElementById('form_email_alerts').value = 'NO'
    }
}

<ul class="confirm details">
  <li class="selected">Please confirm your contact preferences</li>
  <li><input type="checkbox" id="email_alerts" value="YES" onclick="myCheck()"> Receive email alerts</li>
  <li><input type="checkbox" id="sms_alerts" value="NO" onclick="myCheck()"> Receive free SMS alerts</li>
  <li><input type="checkbox" id="offers_alerts" value="NO" onclick="myCheck()"> Receive offers and discounts</li>
  <li><input type="checkbox" id="instant_alerts" value="NO" onclick="myCheck()"> Receive Instant Notifications</li>
</ul>
    
<input id="form_email_alerts" type="hidden" value="">
<input id="form_sms_alerts" type="hidden" value="">
<input id="form_offers_alerts" type="hidden" value="">
<input id="form_instant_alerts" type="hidden" value="">

 

I could add this 4 times or more with different ID but can I just loop through so be quicker and cleaner? I have tried but cant get it to change the hidden values. Thanks