title: In vuejs, why I need to use nextTick while use mounted hooks?
body: <p>As the <a href="https://v2.vuejs.org/v2/guide/migration.html#ready-replaced" rel="nofollow noreferrer">docs</a> said, I need to use nextTick to confirm <code>$el</code> ready, but in another <a href="https://v2.vuejs.org/v2/api/#mounted" rel="nofollow noreferrer">page</a>, it roughly means that the <code>$el</code> has been ready while <code>mounted</code> called. So, why need to use nextTick while use mounted hooks?</p>