get multiple values from dropdownlist in JavaScript

Question

How can I get the values selected in the drop-down list, using a JavaScript function? User can select multiple values from both the elements. Following are the elements

Answer 1

An ES6/functional style alternative to the accepted answer:

const values = Array.apply(null, e.target.options)
  .filter(option => option.selected)
  .map(option => option.value);