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<div class="refnamediv">
<h1 class="refname">preg_grep</h1>
<p class="verinfo">(PHP 4, PHP 5)</p><p class="refpurpose"><span class="refname">preg_grep</span> — <span class="dc-title">Return array entries that match the pattern</span></p>
</div>
<div class="refsect1 description" id="refsect1-function.preg-grep-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type">array</span> <span class="methodname"><strong>preg_grep</strong></span>
( <span class="methodparam"><span class="type">string</span> <code class="parameter">$pattern</code></span>
, <span class="methodparam"><span class="type">array</span> <code class="parameter">$input</code></span>
[, <span class="methodparam"><span class="type">int</span> <code class="parameter">$flags</code><span class="initializer"> = 0</span></span>
] )</div>
<p class="para rdfs-comment">
Returns the array consisting of the elements of the
<em><code class="parameter">input</code></em> array that match the given
<em><code class="parameter">pattern</code></em>.
</p>
</div>
<div class="refsect1 parameters" id="refsect1-function.preg-grep-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<span class="term"><em><code class="parameter">pattern</code></em></span>
<dd>
<p class="para">
The pattern to search for, as a string.
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">input</code></em></span>
<dd>
<p class="para">
The input array.
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">flags</code></em></span>
<dd>
<p class="para">
If set to <strong><code>PREG_GREP_INVERT</code></strong>, this function returns
the elements of the input array that do <em class="emphasis">not</em> match
the given <em><code class="parameter">pattern</code></em>.
</p>
</dd>
</dt>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.preg-grep-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
Returns an array indexed using the keys from the
<em><code class="parameter">input</code></em> array.
</p>
</div>
<div class="refsect1 changelog" id="refsect1-function.preg-grep-changelog">
<h3 class="title">Changelog</h3>
<p class="para">
<table class="doctable informaltable">
<thead>
<tr>
<th>Version</th>
<th>Description</th>
</tr>
</thead>
<tbody class="tbody">
<tr>
<td>4.2.0</td>
<td>
The <em><code class="parameter">flags</code></em> parameter was added.
</td>
</tr>
<tr>
<td>4.0.4</td>
<td>
<p class="para">
Prior to this version, the returned array was indexed regardless of
the keys of the <em><code class="parameter">input</code></em> array.
</p>
<p class="para">
If you want to reproduce this old behavior, use
<span class="function"><a href="function.array-values.html" class="function">array_values()</a></span> on the returned array to reindex
the values.
</p>
</td>
</tr>
</tbody>
</table>
</p>
</div>
<div class="refsect1 examples" id="refsect1-function.preg-grep-examples">
<h3 class="title">Examples</h3>
<p class="para">
<div class="example" id="example-4783">
<p><strong>Example #1 <span class="function"><strong>preg_grep()</strong></span> example</strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br /></span><span style="color: #FF8000">// return all array elements<br />// containing floating point numbers<br /></span><span style="color: #0000BB">$fl_array </span><span style="color: #007700">= </span><span style="color: #0000BB">preg_grep</span><span style="color: #007700">(</span><span style="color: #DD0000">"/^(\d+)?\.\d+$/"</span><span style="color: #007700">, </span><span style="color: #0000BB">$array</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
</div>
</p>
</div>
<div class="refsect1 seealso" id="refsect1-function.preg-grep-seealso">
<h3 class="title">See Also</h3>
<p class="para">
<ul class="simplelist">
<li class="member"><a href="pcre.pattern.html" class="link">PCRE Patterns</a></li>
<li class="member"> <span class="function"><a href="function.preg-match-all.html" class="function" rel="rdfs-seeAlso">preg_match_all()</a> - Perform a global regular expression match</span></li>
<li class="member"> <span class="function"><a href="function.preg-filter.html" class="function" rel="rdfs-seeAlso">preg_filter()</a> - Perform a regular expression search and replace</span></li>
<li class="member"> <span class="function"><a href="function.preg-last-error.html" class="function" rel="rdfs-seeAlso">preg_last_error()</a> - Returns the error code of the last PCRE regex execution</span></li>
</ul>
</p>
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