title: How can I combine class with class that has condition? vue.js 2
body: <p>My vue component is like this :</p>
  
  <pre><code>&lt;template&gt;
      &lt;a class="btn btn-block" :class="[response == 'responseFound' ? ' btn-yellow' : ' btn-default']"&gt;
      ...
      &lt;/a&gt;
   &lt;/template&gt;
  </code></pre>
  
  <p>It works</p>
  
  <p>But, I want to combine it to be one class</p>
  
  <p>I try like this :</p>
  
  <pre><code>&lt;template&gt;
      &lt;a :class="'btn' [response == 'responseFound' ? ' btn-yellow' : ' btn-default'] ' btn-block'"&gt;
      ...
      &lt;/a&gt;
   &lt;/template&gt;
  </code></pre>
  
  <p>But it does not work</p>
  
  <p>How can I solve it?</p>