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| 22 | <title>Conditional Rules (GNU C Language Manual)</title>
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| 30 | <link href="Symbol-Index.html" rel="index" title="Symbol Index">
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| 31 | <link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
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| 32 | <link href="Conditional-Expression.html" rel="up" title="Conditional Expression">
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| 33 | <link href="Conditional-Branches.html" rel="next" title="Conditional Branches">
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| 34 | <link href="Conditional-Expression.html" rel="prev" title="Conditional Expression">
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| 57 | <body lang="en">
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| 58 | <span id="Conditional-Rules"></span><div class="header">
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| 59 | <p>
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| 60 | Next: <a href="Conditional-Branches.html" accesskey="n" rel="next">Conditional Branches</a>, Up: <a href="Conditional-Expression.html" accesskey="u" rel="up">Conditional Expression</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Symbol-Index.html" title="Index" rel="index">Index</a>]</p>
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| 61 | </div>
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| 62 | <hr>
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| 63 | <span id="Rules-for-Conditional-Operator"></span><h4 class="subsection">8.4.1 Rules for Conditional Operator</h4>
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| 64 |
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| 65 | <p>The first operand, <var>condition</var>, should be a value that can be
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| 66 | compared with zero—a number or a pointer. If it is true (nonzero),
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| 67 | then the conditional expression computes <var>iftrue</var> and its value
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| 68 | becomes the value of the conditional expression. Otherwise the
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| 69 | conditional expression computes <var>iffalse</var> and its value becomes
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| 70 | the value of the conditional expression. The conditional expression
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| 71 | always computes just one of <var>iftrue</var> and <var>iffalse</var>, never both
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| 72 | of them.
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| 73 | </p>
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| 74 | <p>Here’s an example: the absolute value of a number <code>x</code>
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| 75 | can be written as <code>(x >= 0 ? x : -x)</code>.
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| 76 | </p>
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| 77 | <p><strong>Warning:</strong> The conditional expression operators have rather low
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| 78 | syntactic precedence. Except when the conditional expression is used
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| 79 | as an argument in a function call, write parentheses around it. For
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| 80 | clarity, always write parentheses around it if it extends across more
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| 81 | than one line.
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| 82 | </p>
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| 83 | <p>Assignment operators and the comma operator (see <a href="Comma-Operator.html">Comma Operator</a>)
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| 84 | have lower precedence than conditional expression operators, so write
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| 85 | parentheses around those when they appear inside a conditional
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| 86 | expression. See <a href="Order-of-Execution.html">Order of Execution</a>.
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| 87 | </p>
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| 88 |
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| 89 |
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| 90 |
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| 92 | </html>
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