The very first Vue.js example

HTML

<script src="http://vuejs.org/js/vue.min.js"></script>
<div id="demo">
  <select v-model="age">
    <option :value="null" disabled>Select Age</option>
    <option value="1">1 Year</option>
    <option value="11">11 Year</option>
  </select>
</div>

JavaScript

var demo = new Vue({
  el: '#demo',
  data: function() {
    return {
      age: null,
    };
  }
})