|
|
<!DOCTYPE HTML>
|
|
|
<html lang="en" class="light sidebar-visible" dir="ltr">
|
|
|
<head>
|
|
|
<!-- Book generated using mdBook -->
|
|
|
<meta charset="UTF-8">
|
|
|
<title>注释 - Rust 程序设计语言 简体中文版</title>
|
|
|
|
|
|
|
|
|
<!-- Custom HTML head -->
|
|
|
|
|
|
<meta name="description" content="">
|
|
|
<meta name="viewport" content="width=device-width, initial-scale=1">
|
|
|
<meta name="theme-color" content="#ffffff">
|
|
|
|
|
|
<link rel="icon" href="favicon.svg">
|
|
|
<link rel="shortcut icon" href="favicon.png">
|
|
|
<link rel="stylesheet" href="css/variables.css">
|
|
|
<link rel="stylesheet" href="css/general.css">
|
|
|
<link rel="stylesheet" href="css/chrome.css">
|
|
|
<link rel="stylesheet" href="css/print.css" media="print">
|
|
|
|
|
|
<!-- Fonts -->
|
|
|
<link rel="stylesheet" href="FontAwesome/css/font-awesome.css">
|
|
|
<link rel="stylesheet" href="fonts/fonts.css">
|
|
|
|
|
|
<!-- Highlight.js Stylesheets -->
|
|
|
<link rel="stylesheet" id="highlight-css" href="highlight.css">
|
|
|
<link rel="stylesheet" id="tomorrow-night-css" href="tomorrow-night.css">
|
|
|
<link rel="stylesheet" id="ayu-highlight-css" href="ayu-highlight.css">
|
|
|
|
|
|
<!-- Custom theme stylesheets -->
|
|
|
<link rel="stylesheet" href="ferris.css">
|
|
|
<link rel="stylesheet" href="theme/2018-edition.css">
|
|
|
<link rel="stylesheet" href="theme/semantic-notes.css">
|
|
|
<link rel="stylesheet" href="theme/listing.css">
|
|
|
|
|
|
|
|
|
<!-- Provide site root to javascript -->
|
|
|
<script>
|
|
|
var path_to_root = "";
|
|
|
var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "navy" : "light";
|
|
|
</script>
|
|
|
<!-- Start loading toc.js asap -->
|
|
|
<script src="toc.js"></script>
|
|
|
</head>
|
|
|
<body>
|
|
|
<div id="body-container">
|
|
|
<!-- Work around some values being stored in localStorage wrapped in quotes -->
|
|
|
<script>
|
|
|
try {
|
|
|
var theme = localStorage.getItem('mdbook-theme');
|
|
|
var sidebar = localStorage.getItem('mdbook-sidebar');
|
|
|
|
|
|
if (theme.startsWith('"') && theme.endsWith('"')) {
|
|
|
localStorage.setItem('mdbook-theme', theme.slice(1, theme.length - 1));
|
|
|
}
|
|
|
|
|
|
if (sidebar.startsWith('"') && sidebar.endsWith('"')) {
|
|
|
localStorage.setItem('mdbook-sidebar', sidebar.slice(1, sidebar.length - 1));
|
|
|
}
|
|
|
} catch (e) { }
|
|
|
</script>
|
|
|
|
|
|
<!-- Set the theme before any content is loaded, prevents flash -->
|
|
|
<script>
|
|
|
var theme;
|
|
|
try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
|
|
|
if (theme === null || theme === undefined) { theme = default_theme; }
|
|
|
const html = document.documentElement;
|
|
|
html.classList.remove('light')
|
|
|
html.classList.add(theme);
|
|
|
html.classList.add("js");
|
|
|
</script>
|
|
|
|
|
|
<input type="checkbox" id="sidebar-toggle-anchor" class="hidden">
|
|
|
|
|
|
<!-- Hide / unhide sidebar before it is displayed -->
|
|
|
<script>
|
|
|
var sidebar = null;
|
|
|
var sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
|
|
|
if (document.body.clientWidth >= 1080) {
|
|
|
try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
|
|
|
sidebar = sidebar || 'visible';
|
|
|
} else {
|
|
|
sidebar = 'hidden';
|
|
|
}
|
|
|
sidebar_toggle.checked = sidebar === 'visible';
|
|
|
html.classList.remove('sidebar-visible');
|
|
|
html.classList.add("sidebar-" + sidebar);
|
|
|
</script>
|
|
|
|
|
|
<nav id="sidebar" class="sidebar" aria-label="Table of contents">
|
|
|
<!-- populated by js -->
|
|
|
<mdbook-sidebar-scrollbox class="sidebar-scrollbox"></mdbook-sidebar-scrollbox>
|
|
|
<noscript>
|
|
|
<iframe class="sidebar-iframe-outer" src="toc.html"></iframe>
|
|
|
</noscript>
|
|
|
<div id="sidebar-resize-handle" class="sidebar-resize-handle">
|
|
|
<div class="sidebar-resize-indicator"></div>
|
|
|
</div>
|
|
|
</nav>
|
|
|
|
|
|
<div id="page-wrapper" class="page-wrapper">
|
|
|
|
|
|
<div class="page">
|
|
|
<div id="menu-bar-hover-placeholder"></div>
|
|
|
<div id="menu-bar" class="menu-bar sticky">
|
|
|
<div class="left-buttons">
|
|
|
<label id="sidebar-toggle" class="icon-button" for="sidebar-toggle-anchor" title="Toggle Table of Contents" aria-label="Toggle Table of Contents" aria-controls="sidebar">
|
|
|
<i class="fa fa-bars"></i>
|
|
|
</label>
|
|
|
<button id="theme-toggle" class="icon-button" type="button" title="Change theme" aria-label="Change theme" aria-haspopup="true" aria-expanded="false" aria-controls="theme-list">
|
|
|
<i class="fa fa-paint-brush"></i>
|
|
|
</button>
|
|
|
<ul id="theme-list" class="theme-popup" aria-label="Themes" role="menu">
|
|
|
<li role="none"><button role="menuitem" class="theme" id="light">Light</button></li>
|
|
|
<li role="none"><button role="menuitem" class="theme" id="rust">Rust</button></li>
|
|
|
<li role="none"><button role="menuitem" class="theme" id="coal">Coal</button></li>
|
|
|
<li role="none"><button role="menuitem" class="theme" id="navy">Navy</button></li>
|
|
|
<li role="none"><button role="menuitem" class="theme" id="ayu">Ayu</button></li>
|
|
|
</ul>
|
|
|
<button id="search-toggle" class="icon-button" type="button" title="Search. (Shortkey: s)" aria-label="Toggle Searchbar" aria-expanded="false" aria-keyshortcuts="S" aria-controls="searchbar">
|
|
|
<i class="fa fa-search"></i>
|
|
|
</button>
|
|
|
</div>
|
|
|
|
|
|
<h1 class="menu-title">Rust 程序设计语言 简体中文版</h1>
|
|
|
|
|
|
<div class="right-buttons">
|
|
|
<a href="print.html" title="Print this book" aria-label="Print this book">
|
|
|
<i id="print-button" class="fa fa-print"></i>
|
|
|
</a>
|
|
|
<a href="https://github.com/KaiserY/trpl-zh-cn/tree/main" title="Git repository" aria-label="Git repository">
|
|
|
<i id="git-repository-button" class="fa fa-github"></i>
|
|
|
</a>
|
|
|
<a href="https://github.com/KaiserY/trpl-zh-cn/edit/main/src/ch03-04-comments.md" title="Suggest an edit" aria-label="Suggest an edit">
|
|
|
<i id="git-edit-button" class="fa fa-edit"></i>
|
|
|
</a>
|
|
|
|
|
|
</div>
|
|
|
</div>
|
|
|
|
|
|
<div id="search-wrapper" class="hidden">
|
|
|
<form id="searchbar-outer" class="searchbar-outer">
|
|
|
<input type="search" id="searchbar" name="searchbar" placeholder="Search this book ..." aria-controls="searchresults-outer" aria-describedby="searchresults-header">
|
|
|
</form>
|
|
|
<div id="searchresults-outer" class="searchresults-outer hidden">
|
|
|
<div id="searchresults-header" class="searchresults-header"></div>
|
|
|
<ul id="searchresults">
|
|
|
</ul>
|
|
|
</div>
|
|
|
</div>
|
|
|
|
|
|
<!-- Apply ARIA attributes after the sidebar and the sidebar toggle button are added to the DOM -->
|
|
|
<script>
|
|
|
document.getElementById('sidebar-toggle').setAttribute('aria-expanded', sidebar === 'visible');
|
|
|
document.getElementById('sidebar').setAttribute('aria-hidden', sidebar !== 'visible');
|
|
|
Array.from(document.querySelectorAll('#sidebar a')).forEach(function(link) {
|
|
|
link.setAttribute('tabIndex', sidebar === 'visible' ? 0 : -1);
|
|
|
});
|
|
|
</script>
|
|
|
|
|
|
<div id="content" class="content">
|
|
|
<main>
|
|
|
<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 we’re doing something complicated here, long enough that we need
|
|
|
// multiple lines of comments to do it! Whew! Hopefully, this comment will
|
|
|
// explain what’s 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; // I’m 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() {
|
|
|
// I’m 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>
|
|
|
|
|
|
</main>
|
|
|
|
|
|
<nav class="nav-wrapper" aria-label="Page navigation">
|
|
|
<!-- Mobile navigation buttons -->
|
|
|
<a rel="prev" href="ch03-03-how-functions-work.html" class="mobile-nav-chapters previous" title="Previous chapter" aria-label="Previous chapter" aria-keyshortcuts="Left">
|
|
|
<i class="fa fa-angle-left"></i>
|
|
|
</a>
|
|
|
|
|
|
<a rel="next prefetch" href="ch03-05-control-flow.html" class="mobile-nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right">
|
|
|
<i class="fa fa-angle-right"></i>
|
|
|
</a>
|
|
|
|
|
|
<div style="clear: both"></div>
|
|
|
</nav>
|
|
|
</div>
|
|
|
</div>
|
|
|
|
|
|
<nav class="nav-wide-wrapper" aria-label="Page navigation">
|
|
|
<a rel="prev" href="ch03-03-how-functions-work.html" class="nav-chapters previous" title="Previous chapter" aria-label="Previous chapter" aria-keyshortcuts="Left">
|
|
|
<i class="fa fa-angle-left"></i>
|
|
|
</a>
|
|
|
|
|
|
<a rel="next prefetch" href="ch03-05-control-flow.html" class="nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right">
|
|
|
<i class="fa fa-angle-right"></i>
|
|
|
</a>
|
|
|
</nav>
|
|
|
|
|
|
</div>
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
<script>
|
|
|
window.playground_copyable = true;
|
|
|
</script>
|
|
|
|
|
|
|
|
|
<script src="elasticlunr.min.js"></script>
|
|
|
<script src="mark.min.js"></script>
|
|
|
<script src="searcher.js"></script>
|
|
|
|
|
|
<script src="clipboard.min.js"></script>
|
|
|
<script src="highlight.js"></script>
|
|
|
<script src="book.js"></script>
|
|
|
|
|
|
<!-- Custom JS scripts -->
|
|
|
<script src="ferris.js"></script>
|
|
|
|
|
|
|
|
|
</div>
|
|
|
</body>
|
|
|
</html>
|
