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| 31 | <link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
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| 32 | <link href="Comma-Operator.html" rel="up" title="Comma Operator">
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| 33 | <link href="Clean-Comma.html" rel="next" title="Clean Comma">
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| 58 | <span id="Uses-of-Comma"></span><div class="header">
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| 59 | <p>
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| 60 | Next: <a href="Clean-Comma.html" accesskey="n" rel="next">Clean Comma</a>, Up: <a href="Comma-Operator.html" accesskey="u" rel="up">Comma Operator</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="The-Uses-of-the-Comma-Operator"></span><h4 class="subsection">8.5.1 The Uses of the Comma Operator</h4>
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| 64 |
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| 65 | <p>With commas, you can put several expressions into a place that
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| 66 | requires just one expression—for example, in the header of a
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| 67 | <code>for</code> statement. This statement
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| 68 | </p>
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| 69 | <div class="example">
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| 70 | <pre class="example">for (i = 0, j = 10, k = 20; i < n; i++)
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| 71 | </pre></div>
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| 72 |
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| 73 | <p>contains three assignment expressions, to initialize <code>i</code>, <code>j</code>
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| 74 | and <code>k</code>. The syntax of <code>for</code> requires just one expression
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| 75 | for initialization; to include three assignments, we use commas to
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| 76 | bundle them into a single larger expression, <code>i = 0, j = 10, k =
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| 77 | 20</code>. This technique is also useful in the loop-advance expression,
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| 78 | the last of the three inside the <code>for</code> parentheses.
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| 79 | </p>
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| 80 | <p>In the <code>for</code> statement and the <code>while</code> statement
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| 81 | (see <a href="Loop-Statements.html">Loop Statements</a>), a comma provides a way to perform some side
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| 82 | effect before the loop-exit test. For example,
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| 83 | </p>
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| 84 | <div class="example">
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| 85 | <pre class="example">while (printf ("At the test, x = %d\n", x), x != 0)
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| 86 | </pre></div>
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| 87 |
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| 90 |
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