title: How to set "all values" as default in a multiple select?
body: <p>There are questions on how to make one selection default, like <a href="https://stackoverflow.com/q/3518002/1801588">this one</a>. But I have a multiple select and want all the options to be selected initially. I found questions for something similar (like <a href="https://stackoverflow.com/q/15696415/1801588">this</a>), but not exactly what I want.</p>
  
  <p>Is this possible without JavaScript?</p>