📄 elif.html
字号:
<html lang="en">
<head>
<title>The C Preprocessor</title>
<meta http-equiv="Content-Type" content="text/html">
<meta name="description" content="The C Preprocessor">
<meta name="generator" content="makeinfo 4.3">
<link href="http://www.gnu.org/software/texinfo/" rel="generator-home">
<!--
Copyright © 1987, 1989, 1991, 1992, 1993, 1994, 1995, 1996,
1997, 1998, 1999, 2000, 2001, 2002, 2003
Free Software Foundation, Inc.
<p>Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.1 or
any later version published by the Free Software Foundation. A copy of
the license is included in the
section entitled "GNU Free Documentation License".
<p>This manual contains no Invariant Sections. The Front-Cover Texts are
(a) (see below), and the Back-Cover Texts are (b) (see below).
<p>(a) The FSF's Front-Cover Text is:
<p>A GNU Manual
<p>(b) The FSF's Back-Cover Text is:
<p>You have freedom to copy and modify this GNU Manual, like GNU
software. Copies published by the Free Software Foundation raise
funds for GNU development.
-->
</head>
<body>
<div class="node">
<p>
Node:<a name="Elif">Elif</a>,
Previous:<a rel="previous" accesskey="p" href="Else.html#Else">Else</a>,
Up:<a rel="up" accesskey="u" href="Conditional-Syntax.html#Conditional%20Syntax">Conditional Syntax</a>
<hr><br>
</div>
<h4 class="subsection">Elif</h4>
<p>One common case of nested conditionals is used to check for more than two
possible alternatives. For example, you might have
<pre class="example"> #if X == 1
...
#else /* X != 1 */
#if X == 2
...
#else /* X != 2 */
...
#endif /* X != 2 */
#endif /* X != 1 */
</pre>
<p>Another conditional directive, <code>#elif</code>, allows this to be
abbreviated as follows:
<pre class="example"> #if X == 1
...
#elif X == 2
...
#else /* X != 2 and X != 1*/
...
#endif /* X != 2 and X != 1*/
</pre>
<p><code>#elif</code> stands for "else if". Like <code>#else</code>, it goes in the
middle of a conditional group and subdivides it; it does not require a
matching <code>#endif</code> of its own. Like <code>#if</code>, the <code>#elif</code>
directive includes an expression to be tested. The text following the
<code>#elif</code> is processed only if the original <code>#if</code>-condition
failed and the <code>#elif</code> condition succeeds.
<p>More than one <code>#elif</code> can go in the same conditional group. Then
the text after each <code>#elif</code> is processed only if the <code>#elif</code>
condition succeeds after the original <code>#if</code> and all previous
<code>#elif</code> directives within it have failed.
<p><code>#else</code> is allowed after any number of <code>#elif</code> directives, but
<code>#elif</code> may not follow <code>#else</code>.
</body></html>
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -