class="token punctuation">;</span>

states<span class="token punctuation">.</span><span class="token function">mapBy</span><span class="token punctuation">(</span><span class="token string">'capital'</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token comment">//=> ["Honolulu", "Sacramento"]</span>
<span aria-hidden="true" class="line-numbers-rows"><a href="#C4_L1" id=C4_L1></a><a href="#C4_L2" id=C4_L2></a><a href="#C4_L3" id=C4_L3></a><a href="#C4_L4" 