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substr [C++ Reference]
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<h2><a name="substr" id="substr">substr</a></h2>
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<p>
Syntax:
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<pre class="c code c++" style="font-family:monospace;"> <span class="co2">#include <string></span>
<span class="kw4">string</span> substr<span class="br0">(</span> size_type index <span class="sy0">=</span> 0<span class="sy0">,</span> size_type length <span class="sy0">=</span> npos <span class="br0">)</span> <span class="kw4">const</span><span class="sy0">;</span></pre>
<p>
The <code>substr</code> method of the string class returns a substring of the current string, starting at <code>index</code>, and <code>length</code> characters long.
</p>
<p>
If <code>index + length</code> is past the end of the string, then only the remainder of the string starting at <code>index</code> will be returned.
</p>
<p>
If <code>length</code> is omitted, it will default to <code>string::npos</code>, and <code>substr</code> will simply return the remainder of the string starting at <code>index</code>.
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<p>
For example:
</p>
<pre class="c code c++" style="font-family:monospace;"> <span class="kw4">string</span> s<span class="br0">(</span><span class="st0">"What we have here is a failure to communicate"</span><span class="br0">)</span><span class="sy0">;</span>
<span class="kw4">string</span> sub <span class="sy0">=</span> s.<span class="me1">substr</span><span class="br0">(</span>21<span class="br0">)</span><span class="sy0">;</span>
<a href="http://www.opengroup.org/onlinepubs/009695399/functions/cout.html"><span class="kw3">cout</span></a> <span class="sy0"><<</span> <span class="st0">"The original string is "</span> <span class="sy0"><<</span> s <span class="sy0"><<</span> endl<span class="sy0">;</span>
<a href="http://www.opengroup.org/onlinepubs/009695399/functions/cout.html"><span class="kw3">cout</span></a> <span class="sy0"><<</span> <span class="st0">"The substring is "</span> <span class="sy0"><<</span> sub <span class="sy0"><<</span> endl<span class="sy0">;</span></pre>
<p>
displays
</p>
<pre class="code">
The original string is What we have here is a failure to communicate
The substring is a failure to communicate</pre>
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Related Topics: <a href="../string/copy.html" class="wikilink1" title="string:copy">copy</a>
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