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77 lines
3.1 KiB
HTML
77 lines
3.1 KiB
HTML
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<title>Else - The C Preprocessor</title>
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under the terms of the GNU Free Documentation License, Version 1.3 or
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any later version published by the Free Software Foundation. A copy of
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the license is included in the
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section entitled ``GNU Free Documentation License''.
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(a) The FSF's Front-Cover Text is:
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A GNU Manual
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<div class="node">
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<a name="Else"></a>
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<p>
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Next: <a rel="next" accesskey="n" href="Elif.html#Elif">Elif</a>,
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Previous: <a rel="previous" accesskey="p" href="Defined.html#Defined">Defined</a>,
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Up: <a rel="up" accesskey="u" href="Conditional-Syntax.html#Conditional-Syntax">Conditional Syntax</a>
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</div>
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<h4 class="subsection">4.2.4 Else</h4>
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<p><a name="index-g_t_0023else-90"></a>The ‘<samp><span class="samp">#else</span></samp>’ directive can be added to a conditional to provide
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alternative text to be used if the condition fails. This is what it
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looks like:
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<pre class="smallexample"> #if <var>expression</var>
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<var>text-if-true</var>
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#else /* Not <var>expression</var> */
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<var>text-if-false</var>
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#endif /* Not <var>expression</var> */
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</pre>
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<p class="noindent">If <var>expression</var> is nonzero, the <var>text-if-true</var> is included and
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the <var>text-if-false</var> is skipped. If <var>expression</var> is zero, the
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opposite happens.
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<p>You can use ‘<samp><span class="samp">#else</span></samp>’ with ‘<samp><span class="samp">#ifdef</span></samp>’ and ‘<samp><span class="samp">#ifndef</span></samp>’, too.
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</body></html>
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