l datatype in Janet. Arrays are values that contain
a sequence of other values, indexed from 0. Arrays are also mutable, meaning
that values can be added or removed in place. Many functions in the Janet core
library will also create arrays, such as <code class="mendoza-code">map</code>, <code class="mendoza-code">filter</code>, and <code class="mendoza-code">interpose</code>.
</p>
<h2>Array Length
</h2>
<p>The length of an array is the number of elements in the array. The last element
of the array is theref