<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <title>Sort an array</title> </head> <body><div class="manualnavbar" style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="function.sizeof.html">sizeof</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.uasort.html">uasort</a></div> <div class="up"><a href="ref.array.html">Array Functions</a></div> <div class="home"><a href="index.html">PHP Manual</a></div> </div><hr /><div id="function.sort" class="refentry"> <div class="refnamediv"> <h1 class="refname">sort</h1> <p class="verinfo">(PHP 4, PHP 5)</p><p class="refpurpose"><span class="refname">sort</span> — <span class="dc-title">Sort an array</span></p> </div> <div class="refsect1 description" id="refsect1-function.sort-description"> <h3 class="title">Description</h3> <div class="methodsynopsis dc-description"> <span class="type">bool</span> <span class="methodname"><strong>sort</strong></span> ( <span class="methodparam"><span class="type">array</span> <code class="parameter reference">&$array</code></span> [, <span class="methodparam"><span class="type">int</span> <code class="parameter">$sort_flags</code><span class="initializer"> = SORT_REGULAR</span></span> ] )</div> <p class="para rdfs-comment"> This function sorts an array. Elements will be arranged from lowest to highest when this function has completed. </p> </div> <div class="refsect1 parameters" id="refsect1-function.sort-parameters"> <h3 class="title">Parameters</h3> <p class="para"> <dl> <dt> <span class="term"><em><code class="parameter">array</code></em></span> <dd> <p class="para"> The input array. </p> </dd> </dt> <dt> <span class="term"><em><code class="parameter">sort_flags</code></em></span> <dd> <p class="para"> The optional second parameter <em><code class="parameter">sort_flags</code></em> may be used to modify the sorting behavior using these values: </p> <p class="para"> Sorting type flags: <ul class="itemizedlist"> <li class="listitem"> <span class="simpara"><strong><code>SORT_REGULAR</code></strong> - compare items normally (don't change types)</span> </li> <li class="listitem"> <span class="simpara"><strong><code>SORT_NUMERIC</code></strong> - compare items numerically</span> </li> <li class="listitem"> <span class="simpara"><strong><code>SORT_STRING</code></strong> - compare items as strings</span> </li> <li class="listitem"> <span class="simpara"> <strong><code>SORT_LOCALE_STRING</code></strong> - compare items as strings, based on the current locale. It uses the locale, which can be changed using <span class="function"><a href="function.setlocale.html" class="function">setlocale()</a></span> </span> </li> <li class="listitem"> <span class="simpara"> <strong><code>SORT_NATURAL</code></strong> - compare items as strings using "natural ordering" like <span class="function"><a href="function.natsort.html" class="function">natsort()</a></span> </span> </li> <li class="listitem"> <span class="simpara"> <strong><code>SORT_FLAG_CASE</code></strong> - can be combined (bitwise OR) with <strong><code>SORT_STRING</code></strong> or <strong><code>SORT_NATURAL</code></strong> to sort strings case-insensitively </span> </li> </ul> </p> </dd> </dt> </dl> </p> </div> <div class="refsect1 returnvalues" id="refsect1-function.sort-returnvalues"> <h3 class="title">Return Values</h3> <p class="para"> Returns <strong><code>TRUE</code></strong> on success or <strong><code>FALSE</code></strong> on failure. </p> </div> <div class="refsect1 changelog" id="refsect1-function.sort-changelog"> <h3 class="title">Changelog</h3> <table class="doctable informaltable"> <thead> <tr> <th>Version</th> <th>Description</th> </tr> </thead> <tbody class="tbody"> <tr> <td>5.4.0</td> <td> Added support for <strong><code>SORT_NATURAL</code></strong> and <strong><code>SORT_FLAG_CASE</code></strong> as <em><code class="parameter">sort_flags</code></em> </td> </tr> <tr> <td>5.0.2</td> <td> Added <strong><code>SORT_LOCALE_STRING</code></strong> </td> </tr> </tbody> </table> </div> <div class="refsect1 examples" id="refsect1-function.sort-examples"> <h3 class="title">Examples</h3> <p class="para"> <div class="example" id="example-5032"> <p><strong>Example #1 <span class="function"><strong>sort()</strong></span> example</strong></p> <div class="example-contents"> <div class="phpcode"><code><span style="color: #000000"> <span style="color: #0000BB"><?php<br /><br />$fruits </span><span style="color: #007700">= array(</span><span style="color: #DD0000">"lemon"</span><span style="color: #007700">, </span><span style="color: #DD0000">"orange"</span><span style="color: #007700">, </span><span style="color: #DD0000">"banana"</span><span style="color: #007700">, </span><span style="color: #DD0000">"apple"</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">sort</span><span style="color: #007700">(</span><span style="color: #0000BB">$fruits</span><span style="color: #007700">);<br />foreach (</span><span style="color: #0000BB">$fruits </span><span style="color: #007700">as </span><span style="color: #0000BB">$key </span><span style="color: #007700">=> </span><span style="color: #0000BB">$val</span><span style="color: #007700">) {<br /> echo </span><span style="color: #DD0000">"fruits[" </span><span style="color: #007700">. </span><span style="color: #0000BB">$key </span><span style="color: #007700">. </span><span style="color: #DD0000">"] = " </span><span style="color: #007700">. </span><span style="color: #0000BB">$val </span><span style="color: #007700">. </span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />}<br /><br /></span><span style="color: #0000BB">?></span> </span> </code></div> </div> <div class="example-contents"><p>The above example will output:</p></div> <div class="example-contents screen"> <div class="cdata"><pre> fruits[0] = apple fruits[1] = banana fruits[2] = lemon fruits[3] = orange </pre></div> </div> </div> </p> <p class="para"> The fruits have been sorted in alphabetical order. </p> <p class="para"> <div class="example" id="example-5033"> <p><strong>Example #2 <span class="function"><strong>sort()</strong></span> example using case-insensitive natural ordering</strong></p> <div class="example-contents"> <div class="phpcode"><code><span style="color: #000000"> <span style="color: #0000BB"><?php<br /><br />$fruits </span><span style="color: #007700">= array(<br /> </span><span style="color: #DD0000">"Orange1"</span><span style="color: #007700">, </span><span style="color: #DD0000">"orange2"</span><span style="color: #007700">, </span><span style="color: #DD0000">"Orange3"</span><span style="color: #007700">, </span><span style="color: #DD0000">"orange20"<br /></span><span style="color: #007700">);<br /></span><span style="color: #0000BB">sort</span><span style="color: #007700">(</span><span style="color: #0000BB">$fruits</span><span style="color: #007700">, </span><span style="color: #0000BB">SORT_NATURAL </span><span style="color: #007700">| </span><span style="color: #0000BB">SORT_FLAG_CASE</span><span style="color: #007700">);<br />foreach (</span><span style="color: #0000BB">$fruits </span><span style="color: #007700">as </span><span style="color: #0000BB">$key </span><span style="color: #007700">=> </span><span style="color: #0000BB">$val</span><span style="color: #007700">) {<br /> echo </span><span style="color: #DD0000">"fruits[" </span><span style="color: #007700">. </span><span style="color: #0000BB">$key </span><span style="color: #007700">. </span><span style="color: #DD0000">"] = " </span><span style="color: #007700">. </span><span style="color: #0000BB">$val </span><span style="color: #007700">. </span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />}<br /><br /></span><span style="color: #0000BB">?></span> </span> </code></div> </div> <div class="example-contents"><p>The above example will output:</p></div> <div class="example-contents screen"> <div class="cdata"><pre> fruits[0] = Orange1 fruits[1] = orange2 fruits[2] = Orange3 fruits[3] = orange20 </pre></div> </div> </div> </p> <p class="para"> The fruits have been sorted like <span class="function"><a href="function.natcasesort.html" class="function">natcasesort()</a></span>. </p> </div> <div class="refsect1 notes" id="refsect1-function.sort-notes"> <h3 class="title">Notes</h3> <blockquote class="note"><p><strong class="note">Note</strong>: <span class="simpara">This function assigns new keys to the elements in <em><code class="parameter">array</code></em>. It will remove any existing keys that may have been assigned, rather than just reordering the keys.</span></p></blockquote> <blockquote class="note"><p><strong class="note">Note</strong>: <span class="simpara"> Like most PHP sorting functions, <span class="function"><strong>sort()</strong></span> uses an implementation of <a href="http://en.wikipedia.org/wiki/Quicksort" class="link external">» Quicksort</a>. The pivot is chosen in the middle of the partition resulting in an optimal time for already sorted arrays. This is however an implementation detail you shouldn't rely on. </span> </p></blockquote> <div class="warning"><strong class="warning">Warning</strong> <p class="simpara"> Be careful when sorting arrays with mixed types values because <span class="function"><strong>sort()</strong></span> can produce unpredictable results. </p> </div> </div> <div class="refsect1 seealso" id="refsect1-function.sort-seealso"> <h3 class="title">See Also</h3> <p class="para"> <ul class="simplelist"> <li class="member"> <span class="function"><a href="function.asort.html" class="function" rel="rdfs-seeAlso">asort()</a> - Sort an array and maintain index association</span></li> <li class="member">The <a href="array.sorting.html" class="link">comparison of array sorting functions</a></li> </ul> </p> </div> </div><hr /><div class="manualnavbar" style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="function.sizeof.html">sizeof</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.uasort.html">uasort</a></div> <div class="up"><a href="ref.array.html">Array Functions</a></div> <div class="home"><a href="index.html">PHP Manual</a></div> </div></body></html>