<?php
include_once $_SERVER['DOCUMENT_ROOT'] . '/include/shared-manual.inc';
$TOC = array();
$TOC_DEPRECATED = array();
$PARENTS = array();
include_once dirname(__FILE__) ."/toc/class.arrayobject.inc";
$setup = array (
  'home' => 
  array (
    0 => 'index.php',
    1 => 'PHP Manual',
  ),
  'head' => 
  array (
    0 => 'UTF-8',
    1 => 'it',
  ),
  'this' => 
  array (
    0 => 'arrayobject.uksort.php',
    1 => 'ArrayObject::uksort',
    2 => 'Sort the entries by keys using a user-defined comparison function',
  ),
  'up' => 
  array (
    0 => 'class.arrayobject.php',
    1 => 'ArrayObject',
  ),
  'prev' => 
  array (
    0 => 'arrayobject.uasort.php',
    1 => 'ArrayObject::uasort',
  ),
  'next' => 
  array (
    0 => 'arrayobject.unserialize.php',
    1 => 'ArrayObject::unserialize',
  ),
  'alternatives' => 
  array (
  ),
  'source' => 
  array (
    'lang' => 'en',
    'path' => 'reference/spl/arrayobject/uksort.xml',
  ),
  'history' => 
  array (
  ),
);
$setup["toc"] = $TOC;
$setup["toc_deprecated"] = $TOC_DEPRECATED;
$setup["parents"] = $PARENTS;
manual_setup($setup);

contributors($setup);

?>
<div id="arrayobject.uksort" class="refentry">
 <div class="refnamediv">
  <h1 class="refname">ArrayObject::uksort</h1>
  <p class="verinfo">(PHP 5 &gt;= 5.2.0, PHP 7, PHP 8)</p><p class="refpurpose"><span class="refname">ArrayObject::uksort</span> &mdash; <span class="dc-title">Sort the entries by keys using a user-defined comparison function</span></p>

 </div>
 <div class="refsect1 description" id="refsect1-arrayobject.uksort-description">
  <h3 class="title">Descrizione</h3>
  <div class="methodsynopsis dc-description">
   <span class="modifier">public</span> <span class="methodname"><strong>ArrayObject::uksort</strong></span>(<span class="methodparam"><span class="type"><a href="language.types.callable.php" class="type callable">callable</a></span> <code class="parameter">$callback</code></span>): <span class="type"><a href="language.types.singleton.php" class="type true">true</a></span></div>

  <p class="para rdfs-comment">
   This function sorts the keys of the entries using a user-supplied
   comparison function. The key to entry correlations will be maintained.
  </p>
  <blockquote class="note"><p><strong class="note">Nota</strong>: 
 <p class="para">
  If two members compare as equal, they retain their original order.
  Prior to PHP 8.0.0, their relative order in the sorted array was undefined.
 </p>
</p></blockquote>

 </div>


 <div class="refsect1 parameters" id="refsect1-arrayobject.uksort-parameters">
  <h3 class="title">Elenco dei parametri</h3>
  <p class="para">
   <dl>
    
     <dt><code class="parameter">callback</code></dt>
     <dd>
      <p class="para">
 La funzione di confronto deve restituire un intero minore, uguale o maggiore di zero se il primo argomento è considerato essere minore, uguale o maggiore del secondo.
</p>
<div class="methodsynopsis dc-description"><span class="methodname"><span class="replaceable">callback</span></span>(<span class="methodparam"><span class="type"><a href="language.types.mixed.php" class="type mixed">mixed</a></span> <code class="parameter">$a</code></span>, <span class="methodparam"><span class="type"><a href="language.types.mixed.php" class="type mixed">mixed</a></span> <code class="parameter">$b</code></span>): <span class="type"><a href="language.types.integer.php" class="type int">int</a></span></div>

<div class="caution"><strong class="caution">Attenzione</strong>
 <p class="para">
  Returning <em>non-integer</em> values from the comparison
  function, such as <span class="type"><a href="language.types.float.php" class="type float">float</a></span>, will result in an internal cast to
  <span class="type"><a href="language.types.integer.php" class="type int">int</a></span> of the callback&#039;s return value. So values such as
  <code class="literal">0.99</code> and <code class="literal">0.1</code> will both be cast to an
  integer value of <code class="literal">0</code>, which will compare such values as equal.
 </p>
</div>
     </dd>
    
   </dl>
  </p>
 </div>


 <div class="refsect1 returnvalues" id="refsect1-arrayobject.uksort-returnvalues">
  <h3 class="title">Valori restituiti</h3>
  <p class="para">
   Always returns <strong><code><a href="reserved.constants.php#constant.true">true</a></code></strong>.
  </p>
 </div>


 <div class="refsect1 changelog" id="refsect1-arrayobject.uksort-changelog">
  <h3 class="title">Log delle modifiche</h3>
  <p class="para">
   <table class="doctable informaltable">
    
     <thead>
      <tr>
       <th>Versione</th>
       <th>Descrizione</th>
      </tr>

     </thead>

     <tbody class="tbody">
      <tr>
 <td>8.2.0</td>
 <td>
  The return type is <strong><code><a href="reserved.constants.php#constant.true">true</a></code></strong> now; previously, it was <span class="type"><a href="language.types.boolean.php" class="type bool">bool</a></span>.
 </td>
</tr>

     </tbody>
    
   </table>

  </p>
 </div>


 <div class="refsect1 examples" id="refsect1-arrayobject.uksort-examples">
  <h3 class="title">Esempi</h3>
  <p class="para">
   <div class="example" id="example-1">
    <p><strong>Example #1 <span class="function"><strong>ArrayObject::uksort()</strong></span> example</strong></p>
    <div class="example-contents">
<div class="phpcode"><code><span style="color: #000000"><span style="color: #0000BB">&lt;?php<br /></span><span style="color: #007700">function </span><span style="color: #0000BB">cmp</span><span style="color: #007700">(</span><span style="color: #0000BB">$a</span><span style="color: #007700">, </span><span style="color: #0000BB">$b</span><span style="color: #007700">) {<br />    </span><span style="color: #0000BB">$a </span><span style="color: #007700">= </span><span style="color: #0000BB">preg_replace</span><span style="color: #007700">(</span><span style="color: #DD0000">'@^(a|an|the) @'</span><span style="color: #007700">, </span><span style="color: #DD0000">''</span><span style="color: #007700">, </span><span style="color: #0000BB">$a</span><span style="color: #007700">);<br />    </span><span style="color: #0000BB">$b </span><span style="color: #007700">= </span><span style="color: #0000BB">preg_replace</span><span style="color: #007700">(</span><span style="color: #DD0000">'@^(a|an|the) @'</span><span style="color: #007700">, </span><span style="color: #DD0000">''</span><span style="color: #007700">, </span><span style="color: #0000BB">$b</span><span style="color: #007700">);<br />    return </span><span style="color: #0000BB">strcasecmp</span><span style="color: #007700">(</span><span style="color: #0000BB">$a</span><span style="color: #007700">, </span><span style="color: #0000BB">$b</span><span style="color: #007700">);<br />}<br /><br /></span><span style="color: #0000BB">$array </span><span style="color: #007700">= array(</span><span style="color: #DD0000">"John" </span><span style="color: #007700">=&gt; </span><span style="color: #0000BB">1</span><span style="color: #007700">, </span><span style="color: #DD0000">"the Earth" </span><span style="color: #007700">=&gt; </span><span style="color: #0000BB">2</span><span style="color: #007700">, </span><span style="color: #DD0000">"an apple" </span><span style="color: #007700">=&gt; </span><span style="color: #0000BB">3</span><span style="color: #007700">, </span><span style="color: #DD0000">"a banana" </span><span style="color: #007700">=&gt; </span><span style="color: #0000BB">4</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$arrayObject </span><span style="color: #007700">= new </span><span style="color: #0000BB">ArrayObject</span><span style="color: #007700">(</span><span style="color: #0000BB">$array</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$arrayObject</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">uksort</span><span style="color: #007700">(</span><span style="color: #DD0000">'cmp'</span><span style="color: #007700">);<br /><br />foreach (</span><span style="color: #0000BB">$arrayObject </span><span style="color: #007700">as </span><span style="color: #0000BB">$key </span><span style="color: #007700">=&gt; </span><span style="color: #0000BB">$value</span><span style="color: #007700">) {<br />    echo </span><span style="color: #DD0000">"</span><span style="color: #0000BB">$key</span><span style="color: #DD0000">: </span><span style="color: #0000BB">$value</span><span style="color: #DD0000">\n"</span><span style="color: #007700">;<br />}<br /></span><span style="color: #0000BB">?&gt;</span></span></code></div>
    </div>

    <div class="example-contents"><p>Il precedente esempio visualizzerà:</p></div>
    <div class="example-contents screen">
<div class="examplescode"><pre class="examplescode">an apple: 3
a banana: 4
the Earth: 2
John: 1</pre>
</div>
    </div>
   </div>
  </p>
 </div>


 <div class="refsect1 seealso" id="refsect1-arrayobject.uksort-seealso">
  <h3 class="title">Vedere anche:</h3>
  <p class="para">
   <ul class="simplelist">
    <li><span class="methodname"><a href="arrayobject.asort.php" class="methodname" rel="rdfs-seeAlso">ArrayObject::asort()</a> - Sort the entries by value</span></li>
    <li><span class="methodname"><a href="arrayobject.ksort.php" class="methodname" rel="rdfs-seeAlso">ArrayObject::ksort()</a> - Sort the entries by key</span></li>
    <li><span class="methodname"><a href="arrayobject.natsort.php" class="methodname" rel="rdfs-seeAlso">ArrayObject::natsort()</a> - Sort entries using a &quot;natural order&quot; algorithm</span></li>
    <li><span class="methodname"><a href="arrayobject.natcasesort.php" class="methodname" rel="rdfs-seeAlso">ArrayObject::natcasesort()</a> - Sort an array using a case insensitive &quot;natural order&quot; algorithm</span></li>
    <li><span class="methodname"><a href="arrayobject.uasort.php" class="methodname" rel="rdfs-seeAlso">ArrayObject::uasort()</a> - Sort the entries with a user-defined comparison function and maintain key association</span></li>
    <li><span class="function"><a href="function.uksort.php" class="function" rel="rdfs-seeAlso">uksort()</a> - Ordina rispetto alle chiavi di un array mediante una funzione definita dall'utente</span></li>
   </ul>
  </p>
 </div>


</div><?php manual_footer($setup); ?>