<span class="hljs-keyword">var</span> f = <span class="hljs-function"><span class="hljs-params">x</span> =&gt;</span> x;
f(<span class="hljs-function"><span class="hljs-params">x</span> =&gt;</span> x + <span class="hljs-function">(<span class="hljs-params">y=<span class="hljs-number">2</span>, z=<span class="hljs-literal">undefined</span>, ...rest</span>) =&gt;</span> y);
<span class="hljs-function"><span class="hljs-params">()</span> =&gt;</span> <span class="hljs-literal">null</span>;
<span class="hljs-keyword">const</span> FC = <span class="hljs-function"><span class="hljs-params">props</span> =&gt;</span> <span class="xml"><span class="hljs-tag">&lt;<span class="hljs-name">p</span>&gt;</span>functional component<span class="hljs-tag">&lt;/<span class="hljs-name">p</span>&gt;</span></span>;