CHECK BOX TO INPUT

https://stackoverflow.com/questions/45829309/put-value-in-input-box-with-the-same-class-based-from-checked-checkbox-separatel

HTML

<script src="https://code.jquery.com/jquery-1.12.3.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
<link rel="stylesheet" href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
<div class="col-lg-8">
  <div class="pricing-levels-3">
    <p><strong>CHECK BOXES(LIMIT 3)</strong></p>
    <input class="single-checkbox" type="checkbox" name="vehicle" value="Senator 1">Senator 1
    <br>
    <input class="single-checkbox" type="checkbox" name="vehicle" value="Senator 2">Senator 2
    <br>
    <input class="single-checkbox" type="checkbox" name="vehicle" value="Senator 3">Senator 3
    <br>
    <input class="single-checkbox" type="checkbox" name="vehicle" value="Senator 4">Senator 4
    <br>
    <input class="single-checkbox" type="checkbox" name="vehicle" value="Senator 5">Senator 5
    <br>
    <input class="single-checkbox" type="checkbox" name="vehicle" value="Senator 6">Senator 6
    <br>
    <input class="single-checkbox" type="checkbox" name="vehicle" value="Senator 7">Senator 7
    <br>
  </div>
</div>
<div class="col-lg-4">
  <br>

  <input class="senators" id="senators" placeholder="SENATORS" readonly/>
  <input class="senators" id="senators1" placeholder="SENATORS" readonly/>
  <input class="senators" id="senators2" placeholder="SENATORS" readonly />
</div>

JavaScript

var senate = $('.senators');
var limit = 3;
$('input.single-checkbox').on('change', function(evt) {
  if ($(this).siblings(':checked').length >= limit) {
    this.checked = false;
  }
  senate.val(getSelectedSenators());
});

function getSelectedSenators() {
  var senators = "";
  $('input[type="checkbox"]').each(function(i, cb) {
    if ($(this).is(":checked")) {
      senators += $(this).val() + " ";
    }
  });
  return senators;
}