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<title>Computes the difference of arrays using a callback function on the keys for comparison</title>
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<div class="refnamediv">
<h1 class="refname">array_diff_ukey</h1>
<p class="verinfo">(PHP 5 >= 5.1.0)</p><p class="refpurpose"><span class="refname">array_diff_ukey</span> — <span class="dc-title">Computes the difference of arrays using a callback function on the keys for comparison</span></p>
</div>
<div class="refsect1 description" id="refsect1-function.array-diff-ukey-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type">array</span> <span class="methodname"><strong>array_diff_ukey</strong></span>
( <span class="methodparam"><span class="type">array</span> <code class="parameter">$array1</code></span>
, <span class="methodparam"><span class="type">array</span> <code class="parameter">$array2</code></span>
[, <span class="methodparam"><span class="type">array</span> <code class="parameter">$...</code></span>
], <span class="methodparam"><span class="type"><a href="language.types.callable.html" class="type callable">callable</a></span> <code class="parameter">$key_compare_func</code></span>
)</div>
<p class="para rdfs-comment">
Compares the keys from <em><code class="parameter">array1</code></em> against the keys
from <em><code class="parameter">array2</code></em> and returns the difference.
This function is like <span class="function"><a href="function.array-diff.html" class="function">array_diff()</a></span> except the
comparison is done on the keys instead of the values.
</p>
<p class="para">
Unlike <span class="function"><a href="function.array-diff-key.html" class="function">array_diff_key()</a></span> a user supplied callback
function is used for the indices comparison, not internal function.
</p>
</div>
<div class="refsect1 parameters" id="refsect1-function.array-diff-ukey-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<span class="term"><em><code class="parameter">array1</code></em></span>
<dd>
<p class="para">
The array to compare from
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">array2</code></em></span>
<dd>
<p class="para">
An array to compare against
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">...</code></em></span>
<dd>
<p class="para">
More arrays to compare against
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">key_compare_func</code></em></span>
<dd>
<p class="para">
The comparison function must return an integer less than, equal to, or greater than zero if the first argument is considered to be respectively less than, equal to, or greater than the second.
</p>
<div class="methodsynopsis dc-description"><span class="type">int</span> <span class="methodname"><span class="replaceable">callback</span></span> ( <span class="methodparam"><span class="type"><a href="language.pseudo-types.html#language.types.mixed" class="type mixed">mixed</a></span> <code class="parameter">$a</code></span>, <span class="methodparam"><span class="type"><a href="language.pseudo-types.html#language.types.mixed" class="type mixed">mixed</a></span> <code class="parameter">$b</code></span> )</div>
</dd>
</dt>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.array-diff-ukey-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
Returns an <span class="type"><a href="language.types.array.html" class="type array">array</a></span> containing all the entries from
<em><code class="parameter">array1</code></em> that are not present in any of the other arrays.
</p>
</div>
<div class="refsect1 examples" id="refsect1-function.array-diff-ukey-examples">
<h3 class="title">Examples</h3>
<p class="para">
<div class="example" id="example-4941">
<p><strong>Example #1 <span class="function"><strong>array_diff_ukey()</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: #007700">function </span><span style="color: #0000BB">key_compare_func</span><span style="color: #007700">(</span><span style="color: #0000BB">$key1</span><span style="color: #007700">, </span><span style="color: #0000BB">$key2</span><span style="color: #007700">)<br />{<br /> if (</span><span style="color: #0000BB">$key1 </span><span style="color: #007700">== </span><span style="color: #0000BB">$key2</span><span style="color: #007700">)<br /> return </span><span style="color: #0000BB">0</span><span style="color: #007700">;<br /> else if (</span><span style="color: #0000BB">$key1 </span><span style="color: #007700">> </span><span style="color: #0000BB">$key2</span><span style="color: #007700">)<br /> return </span><span style="color: #0000BB">1</span><span style="color: #007700">;<br /> else<br /> return -</span><span style="color: #0000BB">1</span><span style="color: #007700">;<br />}<br /><br /></span><span style="color: #0000BB">$array1 </span><span style="color: #007700">= array(</span><span style="color: #DD0000">'blue' </span><span style="color: #007700">=> </span><span style="color: #0000BB">1</span><span style="color: #007700">, </span><span style="color: #DD0000">'red' </span><span style="color: #007700">=> </span><span style="color: #0000BB">2</span><span style="color: #007700">, </span><span style="color: #DD0000">'green' </span><span style="color: #007700">=> </span><span style="color: #0000BB">3</span><span style="color: #007700">, </span><span style="color: #DD0000">'purple' </span><span style="color: #007700">=> </span><span style="color: #0000BB">4</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$array2 </span><span style="color: #007700">= array(</span><span style="color: #DD0000">'green' </span><span style="color: #007700">=> </span><span style="color: #0000BB">5</span><span style="color: #007700">, </span><span style="color: #DD0000">'blue' </span><span style="color: #007700">=> </span><span style="color: #0000BB">6</span><span style="color: #007700">, </span><span style="color: #DD0000">'yellow' </span><span style="color: #007700">=> </span><span style="color: #0000BB">7</span><span style="color: #007700">, </span><span style="color: #DD0000">'cyan' </span><span style="color: #007700">=> </span><span style="color: #0000BB">8</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">array_diff_ukey</span><span style="color: #007700">(</span><span style="color: #0000BB">$array1</span><span style="color: #007700">, </span><span style="color: #0000BB">$array2</span><span style="color: #007700">, </span><span style="color: #DD0000">'key_compare_func'</span><span style="color: #007700">));<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>
array(2) {
["red"]=>
int(2)
["purple"]=>
int(4)
}
</pre></div>
</div>
</div>
</p>
</div>
<div class="refsect1 notes" id="refsect1-function.array-diff-ukey-notes">
<h3 class="title">Notes</h3>
<blockquote class="note"><p><strong class="note">Note</strong>:
<p class="para">
This function only checks one dimension of a n-dimensional
array. Of course you can check deeper dimensions by using
<em>array_diff_ukey($array1[0], $array2[0], 'callback_func');</em>.
</p>
</p></blockquote>
</div>
<div class="refsect1 seealso" id="refsect1-function.array-diff-ukey-seealso">
<h3 class="title">See Also</h3>
<p class="para">
<ul class="simplelist">
<li class="member"> <span class="function"><a href="function.array-diff.html" class="function" rel="rdfs-seeAlso">array_diff()</a> - Computes the difference of arrays</span></li>
<li class="member"> <span class="function"><a href="function.array-udiff.html" class="function" rel="rdfs-seeAlso">array_udiff()</a> - Computes the difference of arrays by using a callback function for data comparison</span></li>
<li class="member"> <span class="function"><a href="function.array-diff-assoc.html" class="function" rel="rdfs-seeAlso">array_diff_assoc()</a> - Computes the difference of arrays with additional index check</span></li>
<li class="member"> <span class="function"><a href="function.array-diff-uassoc.html" class="function" rel="rdfs-seeAlso">array_diff_uassoc()</a> - Computes the difference of arrays with additional index check which is performed by a user supplied callback function</span></li>
<li class="member"> <span class="function"><a href="function.array-udiff-assoc.html" class="function" rel="rdfs-seeAlso">array_udiff_assoc()</a> - Computes the difference of arrays with additional index check, compares data by a callback function</span></li>
<li class="member"> <span class="function"><a href="function.array-udiff-uassoc.html" class="function" rel="rdfs-seeAlso">array_udiff_uassoc()</a> - Computes the difference of arrays with additional index check, compares data and indexes by a callback function</span></li>
<li class="member"> <span class="function"><a href="function.array-diff-key.html" class="function" rel="rdfs-seeAlso">array_diff_key()</a> - Computes the difference of arrays using keys for comparison</span></li>
<li class="member"> <span class="function"><a href="function.array-intersect.html" class="function" rel="rdfs-seeAlso">array_intersect()</a> - Computes the intersection of arrays</span></li>
<li class="member"> <span class="function"><a href="function.array-intersect-assoc.html" class="function" rel="rdfs-seeAlso">array_intersect_assoc()</a> - Computes the intersection of arrays with additional index check</span></li>
<li class="member"> <span class="function"><a href="function.array-intersect-uassoc.html" class="function" rel="rdfs-seeAlso">array_intersect_uassoc()</a> - Computes the intersection of arrays with additional index check, compares indexes by a callback function</span></li>
<li class="member"> <span class="function"><a href="function.array-intersect-key.html" class="function" rel="rdfs-seeAlso">array_intersect_key()</a> - Computes the intersection of arrays using keys for comparison</span></li>
<li class="member"> <span class="function"><a href="function.array-intersect-ukey.html" class="function" rel="rdfs-seeAlso">array_intersect_ukey()</a> - Computes the intersection of arrays using a callback function on the keys for comparison</span></li>
</ul>
</p>
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