title: How to use v-for on a 2 dimensional array
body: <p>I want to loop through a 2 dimensional array with Vue.js, but when I use a nested <code>v-for</code> inside another <code>v-for</code>, I get this error:</p>
  
  <blockquote>
    <ul>
    <li>invalid v-for alias "case" in expression: v-for="case in line"</li>
    </ul>
  </blockquote>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>new Vue({
    el: "#app",
    data: {
      chessboard: [
        [null,null,null,null],
        [null,null,null,null],
        [null,null,null,null],
        [null,null,null,null]
      ]
    }
  });</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"&gt;&lt;/script&gt;
  &lt;div id="app"&gt;
    &lt;div class="chessboard"&gt;
      &lt;div v-for="line in chessboard"&gt;
        &lt;div v-for="case in line"&gt;
          &lt;button&gt;&lt;/button&gt;
        &lt;/div&gt;
      &lt;/div&gt;
    &lt;/div&gt;
  &lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>
  
  <p>How should I do to make it work?</p>
  
  <p>Thank you for your help.</p>