pre><code class="language-javascript">// PREFER
m(&quot;div&quot;, [
    m(&quot;div&quot;, &quot;a&quot;),
    [
        m(&quot;div&quot;, {key: 1}, &quot;b&quot;),
    ]
])</code></pre>
<p>Note that <code>null</code>s, <code>undefined</code>s and booleans are considered unkeyed nodes. If you want the keyed equivalent, use <code>m.fragment({key: ...}, [])</code> which is a keyed empty fragment.</p>
<pre><code class="language-javascript">// AVOID
m(&quot;div&quot;, [
    a ? m(&quot;div&quot;, {key: 1}, &q