e><!--{{code "/doc/progs/go1.go" `/append.*world/`}}
-->    greeting = append(greeting, &#34;world&#34;...)</pre>

<p>
<em>Updating</em>:
This is a new feature, so existing code needs no changes.
</p>

<h3 id="close">Close</h3>

<p>
The <code>close</code> predeclared function provides a mechanism
for a sender to signal that no more values will be sent.
It is important to the implementation of <code>for</code> <code>range</code>
loops over channels and is helpful in other situations.
Partly by design and par