nums</span>[<span class="tm-num">0</span>] = <span class="tm-num">101</span>; <span class="tm-cmt">// because Javascript arrays are always mutable</span></pre></p>
<p><code>nums</code> has type <code>number[]</code> because <code>1</code>, <code>2</code>, and <code>3</code> individually have
the matching literal types <code>1</code>, <code>2</code>, and <code>3</code>, but each array element
widens the fresh literal type to <code>number</code>.</p>
<p>In addition, mutable locations become non-mutable locati