Edit in JSFiddle

new Vue({
   el: '#app',
   data: {
     message: 'Hello'
   },
   computed: {
     capitalizedMessage: function () {
       return this.message.toUpperCase();
     }
   }
 })
<div id="app">
   <p>Original message: "{{ message }}"</p>
   <p>Capitalized message: "{{ capitalizedMessage }}"</p>
</div>