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malloc [C++ Reference]
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<h2><a name="malloc" id="malloc">malloc</a></h2>
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<p>
Syntax:
</p>
<pre class="c code c++" style="font-family:monospace;"> <span class="co2">#include <cstdlib></span>
<span class="kw4">void</span> <span class="sy0">*</span>malloc<span class="br0">(</span> size_t size <span class="br0">)</span><span class="sy0">;</span></pre>
<p>
The function malloc() returns a pointer to a chunk of memory of size size, or
NULL if there is an error. The memory pointed to will be on the heap, not the
stack, so make sure to free it when you are done with it. An example:
</p>
<pre class="c code c++" style="font-family:monospace;"> <span class="kw4">typedef</span> <span class="kw4">struct</span> data_type <span class="br0">{</span>
<span class="kw4">int</span> age<span class="sy0">;</span>
<span class="kw4">char</span> name<span class="br0">[</span>20<span class="br0">]</span><span class="sy0">;</span>
<span class="br0">}</span> data<span class="sy0">;</span>
data <span class="sy0">*</span>bob<span class="sy0">;</span>
bob <span class="sy0">=</span> <span class="br0">(</span>data<span class="sy0">*</span><span class="br0">)</span> malloc<span class="br0">(</span> <span class="kw4">sizeof</span><span class="br0">(</span>data<span class="br0">)</span> <span class="br0">)</span><span class="sy0">;</span>
<span class="kw1">if</span><span class="br0">(</span> bob <span class="sy0">!=</span> NULL <span class="br0">)</span> <span class="br0">{</span>
bob<span class="sy0">-></span>age <span class="sy0">=</span> <span class="nu0">22</span><span class="sy0">;</span>
strcpy<span class="br0">(</span> bob<span class="sy0">-></span>name<span class="sy0">,</span> <span class="st0">"Robert"</span> <span class="br0">)</span><span class="sy0">;</span>
<a href="http://www.opengroup.org/onlinepubs/009695399/functions/printf.html"><span class="kw3">printf</span></a><span class="br0">(</span> <span class="st0">"%s is %d years old<span class="es1">\n</span>"</span><span class="sy0">,</span> bob<span class="sy0">-></span>name<span class="sy0">,</span> bob<span class="sy0">-></span>age <span class="br0">)</span><span class="sy0">;</span>
<span class="br0">}</span>
free<span class="br0">(</span> bob <span class="br0">)</span><span class="sy0">;</span></pre>
<p>
NOTE that new/delete is preferred in C++ (as opposed to malloc/free in C).
</p>
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Related Topics: <a href="../../c/mem/calloc.html" class="wikilink1" title="c:mem:calloc">calloc</a>, <a href="../../keywords/delete.html" class="wikilink1" title="keywords:delete">delete</a>, <a href="../../c/mem/free.html" class="wikilink1" title="c:mem:free">free</a>, <a href="../../keywords/new.html" class="wikilink1" title="keywords:new">new</a>, <a href="../../c/mem/realloc.html" class="wikilink1" title="c:mem:realloc">realloc</a>
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