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<h2 id="注释"><a class="header" href="#注释">注释</a></h2>
<blockquote>
<p><a href="https://github.com/rust-lang/book/blob/main/src/ch03-04-comments.md">ch03-04-comments.md</a>
<br>
commit d0acb2595c891de97a133d06635c50ab449dd65c</p>
</blockquote>
<p>所有程序员都力求使其代码易于理解,不过有时还需要提供额外的解释。在这种情况下,程序员在源码中留下 <strong>注释</strong><em>comments</em>),编译器会忽略它们,不过阅读代码的人可能觉得有用。</p>
<p>这是一个简单的注释:</p>
<pre><pre class="playground"><code class="language-rust edition2021"><span class="boring">#![allow(unused)]
</span><span class="boring">fn main() {
</span>// hello, world
<span class="boring">}</span></code></pre></pre>
<p>在 Rust 中,惯用的注释样式是以两个斜杠开始注释,并持续到本行的结尾。对于超过一行的注释,需要在每一行前都加上 <code>//</code>,像这样:</p>
<pre><pre class="playground"><code class="language-rust edition2021"><span class="boring">#![allow(unused)]
</span><span class="boring">fn main() {
</span>// So were doing something complicated here, long enough that we need
// multiple lines of comments to do it! Whew! Hopefully, this comment will
// explain whats going on.
<span class="boring">}</span></code></pre></pre>
<p>注释也可以放在包含代码的行的末尾:</p>
<p><span class="filename">文件名src/main.rs</span></p>
<pre><pre class="playground"><code class="language-rust edition2021">fn main() {
let lucky_number = 7; // Im feeling lucky today
}</code></pre></pre>
<p>不过你更经常看到的是以这种格式使用它们,也就是位于它所解释的代码行的上面一行:</p>
<p><span class="filename">文件名src/main.rs</span></p>
<pre><pre class="playground"><code class="language-rust edition2021">fn main() {
// Im feeling lucky today
let lucky_number = 7;
}</code></pre></pre>
<p>Rust 还有另一种注释,称为文档注释,我们将在 14 章的 <a href="ch14-02-publishing-to-crates-io.html">“将 crate 发布到 Crates.io” </a>部分讨论它。</p>
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