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58<span id="Pointers"></span><div class="header">
59<p>
60Next: <a href="Structures.html" accesskey="n" rel="next">Structures</a>, Previous: <a href="Type-Size.html" accesskey="p" rel="prev">Type Size</a>, Up: <a href="index.html" accesskey="u" rel="up">Top</a> &nbsp; [<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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63<span id="Pointers-1"></span><h2 class="chapter">14 Pointers</h2>
64<span id="index-pointers"></span>
65
66<p>Among high-level languages, C is rather low level, close to the
67machine. This is mainly because it has explicit <em>pointers</em>. A
68pointer value is the numeric address of data in memory. The type of
69data to be found at that address is specified by the data type of the
70pointer itself. The unary operator &lsquo;<samp>*</samp>&rsquo; gets the data that a
71pointer points to&mdash;this is called <em>dereferencing the pointer</em>.
72</p>
73<p>C also allows pointers to functions, but since there are some
74differences in how they work, we treat them later. See <a href="Function-Pointers.html">Function Pointers</a>.
75</p>
76<table class="menu" border="0" cellspacing="0">
77<tr><td align="left" valign="top">&bull; <a href="Address-of-Data.html" accesskey="1">Address of Data</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Using the &ldquo;address-of&rdquo; operator.
78</td></tr>
79<tr><td align="left" valign="top">&bull; <a href="Pointer-Types.html" accesskey="2">Pointer Types</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">For each type, there is a pointer type.
80</td></tr>
81<tr><td align="left" valign="top">&bull; <a href="Pointer-Declarations.html" accesskey="3">Pointer Declarations</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Declaring variables with pointer types.
82</td></tr>
83<tr><td align="left" valign="top">&bull; <a href="Pointer-Type-Designators.html" accesskey="4">Pointer Type Designators</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Designators for pointer types.
84</td></tr>
85<tr><td align="left" valign="top">&bull; <a href="Pointer-Dereference.html" accesskey="5">Pointer Dereference</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Accessing what a pointer points at.
86</td></tr>
87<tr><td align="left" valign="top">&bull; <a href="Null-Pointers.html" accesskey="6">Null Pointers</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Pointers which do not point to any object.
88</td></tr>
89<tr><td align="left" valign="top">&bull; <a href="Invalid-Dereference.html" accesskey="7">Invalid Dereference</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Dereferencing null or invalid pointers.
90</td></tr>
91<tr><td align="left" valign="top">&bull; <a href="Void-Pointers.html" accesskey="8">Void Pointers</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Totally generic pointers, can cast to any.
92</td></tr>
93<tr><td align="left" valign="top">&bull; <a href="Pointer-Comparison.html" accesskey="9">Pointer Comparison</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Comparing memory address values.
94</td></tr>
95<tr><td align="left" valign="top">&bull; <a href="Pointer-Arithmetic.html">Pointer Arithmetic</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Computing memory address values.
96</td></tr>
97<tr><td align="left" valign="top">&bull; <a href="Pointers-and-Arrays.html">Pointers and Arrays</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Using pointer syntax instead of array syntax.
98</td></tr>
99<tr><td align="left" valign="top">&bull; <a href="Pointer-Arithmetic-Low-Level.html">Pointer Arithmetic Low Level</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">More about computing memory address values.
100</td></tr>
101<tr><td align="left" valign="top">&bull; <a href="Pointer-Increment_002fDecrement.html">Pointer Increment/Decrement</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Incrementing and decrementing pointers.
102</td></tr>
103<tr><td align="left" valign="top">&bull; <a href="Pointer-Arithmetic-Drawbacks.html">Pointer Arithmetic Drawbacks</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">A common pointer bug to watch out for.
104</td></tr>
105<tr><td align="left" valign="top">&bull; <a href="Pointer_002dInteger-Conversion.html">Pointer-Integer Conversion</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Converting pointer types to integer types.
106</td></tr>
107<tr><td align="left" valign="top">&bull; <a href="Printing-Pointers.html">Printing Pointers</a></td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Using <code>printf</code> for a pointer&rsquo;s value.
108</td></tr>
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