select2/docs/_includes/examples/multiple.html

<section>

  <h1 id="multiple">Multiple select boxes</h1>

  <p>
    Select2 also supports multi-value select boxes. The select below is declared with the <code>multiple</code> attribute.
  </p>

  <div class="s2-example">
    <p>
      <select class="js-example-basic-multiple js-states form-control" multiple="multiple"></select>
    </p>
  </div>

  <pre data-fill-from=".js-code-multiple"></pre>

<script type="text/x-example-code" class="js-code-multiple">
$(".js-example-basic-multiple").select2();

<select class="js-example-basic-multiple" multiple="multiple">
  <option value="AL">Alabama</option>
    ...
  <option value="WY">Wyoming</option>
</select>
</script>

</section>