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  20. <title>Using fast enumeration (Using the GNU Compiler Collection (GCC))</title>
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  29. <link href="Fast-enumeration.html#Fast-enumeration" rel="up" title="Fast enumeration">
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  61. <a name="Using-fast-enumeration"></a>
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  64. Next: <a href="c99_002dlike-fast-enumeration-syntax.html#c99_002dlike-fast-enumeration-syntax" accesskey="n" rel="next">c99-like fast enumeration syntax</a>, Up: <a href="Fast-enumeration.html#Fast-enumeration" accesskey="u" rel="up">Fast enumeration</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p>
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  67. <a name="Using-Fast-Enumeration"></a>
  68. <h4 class="subsection">8.9.1 Using Fast Enumeration</h4>
  69. <p>GNU Objective-C provides support for the fast enumeration syntax:
  70. </p>
  71. <div class="smallexample">
  72. <pre class="smallexample"> id array = &hellip;;
  73. id object;
  74. for (object in array)
  75. {
  76. /* Do something with 'object' */
  77. }
  78. </pre></div>
  79. <p><code>array</code> needs to be an Objective-C object (usually a collection
  80. object, for example an array, a dictionary or a set) which implements
  81. the &ldquo;Fast Enumeration Protocol&rdquo; (see below). If you are using a
  82. Foundation library such as GNUstep Base or Apple Cocoa Foundation, all
  83. collection objects in the library implement this protocol and can be
  84. used in this way.
  85. </p>
  86. <p>The code above would iterate over all objects in <code>array</code>. For
  87. each of them, it assigns it to <code>object</code>, then executes the
  88. <code>Do something with 'object'</code> statements.
  89. </p>
  90. <p>Here is a fully worked-out example using a Foundation library (which
  91. provides the implementation of <code>NSArray</code>, <code>NSString</code> and
  92. <code>NSLog</code>):
  93. </p>
  94. <div class="smallexample">
  95. <pre class="smallexample"> NSArray *array = [NSArray arrayWithObjects: @&quot;1&quot;, @&quot;2&quot;, @&quot;3&quot;, nil];
  96. NSString *object;
  97. for (object in array)
  98. NSLog (@&quot;Iterating over %@&quot;, object);
  99. </pre></div>
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