guments, the data structure, the key, and the value, and returns the data
structure. The allowed types keys and values depend on the data structure passed
in.
</p>
<pre class="mendoza-codeblock"><code data-language="janet">(<span class="mdzsyn-coresym">put</span> @[] <span class="mdzsyn-number">100</span> <span class="mdzsyn-keyword">:a</span>)
(<span class="mdzsyn-coresym">put</span> @{} <span class="mdzsyn-keyword">:key</span> <span class="mdzsyn-string">"value"</span>)
(<span class="mdzsyn-coresym">put</