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<div class="refnamediv">
<h1 class="refname">array_udiff</h1>
<p class="verinfo">(PHP 5)</p><p class="refpurpose"><span class="refname">array_udiff</span> — <span class="dc-title">Computes the difference of arrays by using a callback function for data comparison</span></p>
</div>
<div class="refsect1 description" id="refsect1-function.array-udiff-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type">array</span> <span class="methodname"><strong>array_udiff</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">$...</code></span>
], <span class="methodparam"><span class="type"><a href="language.types.callable.html" class="type callable">callable</a></span> <code class="parameter">$value_compare_func</code></span>
)</div>
<p class="para rdfs-comment">
Computes the difference of arrays by using a callback function for data
comparison. This is unlike <span class="function"><a href="function.array-diff.html" class="function">array_diff()</a></span> which uses an
internal function for comparing the data.
</p>
</div>
<div class="refsect1 parameters" id="refsect1-function.array-udiff-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 first array.
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">array2</code></em></span>
<dd>
<p class="para">
The second array.
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">value_compare_func</code></em></span>
<dd>
<p class="para">
The callback comparison function.
</p>
<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-udiff-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
Returns an array containing all the values of <em><code class="parameter">array1</code></em>
that are not present in any of the other arguments.
</p>
</div>
<div class="refsect1 examples" id="refsect1-function.array-udiff-examples">
<h3 class="title">Examples</h3>
<p class="para">
<div class="example" id="example-4988">
<p><strong>Example #1 <span class="function"><strong>array_udiff()</strong></span> example using stdClass Objects</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">// Arrays to compare<br /></span><span style="color: #0000BB">$array1 </span><span style="color: #007700">= array(new </span><span style="color: #0000BB">stdclass</span><span style="color: #007700">, new </span><span style="color: #0000BB">stdclass</span><span style="color: #007700">,<br /> new </span><span style="color: #0000BB">stdclass</span><span style="color: #007700">, new </span><span style="color: #0000BB">stdclass</span><span style="color: #007700">,<br /> );<br /><br /></span><span style="color: #0000BB">$array2 </span><span style="color: #007700">= array(<br /> new </span><span style="color: #0000BB">stdclass</span><span style="color: #007700">, new </span><span style="color: #0000BB">stdclass</span><span style="color: #007700">,<br /> );<br /><br /></span><span style="color: #FF8000">// Set some properties for each object<br /></span><span style="color: #0000BB">$array1</span><span style="color: #007700">[</span><span style="color: #0000BB">0</span><span style="color: #007700">]-></span><span style="color: #0000BB">width </span><span style="color: #007700">= </span><span style="color: #0000BB">11</span><span style="color: #007700">; </span><span style="color: #0000BB">$array1</span><span style="color: #007700">[</span><span style="color: #0000BB">0</span><span style="color: #007700">]-></span><span style="color: #0000BB">height </span><span style="color: #007700">= </span><span style="color: #0000BB">3</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$array1</span><span style="color: #007700">[</span><span style="color: #0000BB">1</span><span style="color: #007700">]-></span><span style="color: #0000BB">width </span><span style="color: #007700">= </span><span style="color: #0000BB">7</span><span style="color: #007700">; </span><span style="color: #0000BB">$array1</span><span style="color: #007700">[</span><span style="color: #0000BB">1</span><span style="color: #007700">]-></span><span style="color: #0000BB">height </span><span style="color: #007700">= </span><span style="color: #0000BB">1</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$array1</span><span style="color: #007700">[</span><span style="color: #0000BB">2</span><span style="color: #007700">]-></span><span style="color: #0000BB">width </span><span style="color: #007700">= </span><span style="color: #0000BB">2</span><span style="color: #007700">; </span><span style="color: #0000BB">$array1</span><span style="color: #007700">[</span><span style="color: #0000BB">2</span><span style="color: #007700">]-></span><span style="color: #0000BB">height </span><span style="color: #007700">= </span><span style="color: #0000BB">9</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$array1</span><span style="color: #007700">[</span><span style="color: #0000BB">3</span><span style="color: #007700">]-></span><span style="color: #0000BB">width </span><span style="color: #007700">= </span><span style="color: #0000BB">5</span><span style="color: #007700">; </span><span style="color: #0000BB">$array1</span><span style="color: #007700">[</span><span style="color: #0000BB">3</span><span style="color: #007700">]-></span><span style="color: #0000BB">height </span><span style="color: #007700">= </span><span style="color: #0000BB">7</span><span style="color: #007700">;<br /><br /></span><span style="color: #0000BB">$array2</span><span style="color: #007700">[</span><span style="color: #0000BB">0</span><span style="color: #007700">]-></span><span style="color: #0000BB">width </span><span style="color: #007700">= </span><span style="color: #0000BB">7</span><span style="color: #007700">; </span><span style="color: #0000BB">$array2</span><span style="color: #007700">[</span><span style="color: #0000BB">0</span><span style="color: #007700">]-></span><span style="color: #0000BB">height </span><span style="color: #007700">= </span><span style="color: #0000BB">5</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$array2</span><span style="color: #007700">[</span><span style="color: #0000BB">1</span><span style="color: #007700">]-></span><span style="color: #0000BB">width </span><span style="color: #007700">= </span><span style="color: #0000BB">9</span><span style="color: #007700">; </span><span style="color: #0000BB">$array2</span><span style="color: #007700">[</span><span style="color: #0000BB">1</span><span style="color: #007700">]-></span><span style="color: #0000BB">height </span><span style="color: #007700">= </span><span style="color: #0000BB">2</span><span style="color: #007700">;<br /><br />function </span><span style="color: #0000BB">compare_by_area</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">$areaA </span><span style="color: #007700">= </span><span style="color: #0000BB">$a</span><span style="color: #007700">-></span><span style="color: #0000BB">width </span><span style="color: #007700">* </span><span style="color: #0000BB">$a</span><span style="color: #007700">-></span><span style="color: #0000BB">height</span><span style="color: #007700">;<br /> </span><span style="color: #0000BB">$areaB </span><span style="color: #007700">= </span><span style="color: #0000BB">$b</span><span style="color: #007700">-></span><span style="color: #0000BB">width </span><span style="color: #007700">* </span><span style="color: #0000BB">$b</span><span style="color: #007700">-></span><span style="color: #0000BB">height</span><span style="color: #007700">;<br /> <br /> if (</span><span style="color: #0000BB">$areaA </span><span style="color: #007700">< </span><span style="color: #0000BB">$areaB</span><span style="color: #007700">) {<br /> return -</span><span style="color: #0000BB">1</span><span style="color: #007700">;<br /> } elseif (</span><span style="color: #0000BB">$areaA </span><span style="color: #007700">> </span><span style="color: #0000BB">$areaB</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">0</span><span style="color: #007700">;<br /> }<br />}<br /><br /></span><span style="color: #0000BB">print_r</span><span style="color: #007700">(</span><span style="color: #0000BB">array_udiff</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">'compare_by_area'</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
(
[0] => stdClass Object
(
[width] => 11
[height] => 3
)
[1] => stdClass Object
(
[width] => 7
[height] => 1
)
)
</pre></div>
</div>
</div>
</p>
<p class="para">
<div class="example" id="example-4989">
<p><strong>Example #2 <span class="function"><strong>array_udiff()</strong></span> example using DateTime Objects</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">Class </span><span style="color: #0000BB">MyCalendar </span><span style="color: #007700">{<br /> public </span><span style="color: #0000BB">$free </span><span style="color: #007700">= array();<br /> public </span><span style="color: #0000BB">$booked </span><span style="color: #007700">= array();<br /><br /> public function </span><span style="color: #0000BB">__construct</span><span style="color: #007700">(</span><span style="color: #0000BB">$week </span><span style="color: #007700">= </span><span style="color: #DD0000">'now'</span><span style="color: #007700">) {<br /> </span><span style="color: #0000BB">$start </span><span style="color: #007700">= new </span><span style="color: #0000BB">DateTime</span><span style="color: #007700">(</span><span style="color: #0000BB">$week</span><span style="color: #007700">);<br /> </span><span style="color: #0000BB">$start</span><span style="color: #007700">-></span><span style="color: #0000BB">modify</span><span style="color: #007700">(</span><span style="color: #DD0000">'Monday this week midnight'</span><span style="color: #007700">);<br /> </span><span style="color: #0000BB">$end </span><span style="color: #007700">= clone </span><span style="color: #0000BB">$start</span><span style="color: #007700">;<br /> </span><span style="color: #0000BB">$end</span><span style="color: #007700">-></span><span style="color: #0000BB">modify</span><span style="color: #007700">(</span><span style="color: #DD0000">'Friday this week midnight'</span><span style="color: #007700">);<br /> </span><span style="color: #0000BB">$interval </span><span style="color: #007700">= new </span><span style="color: #0000BB">DateInterval</span><span style="color: #007700">(</span><span style="color: #DD0000">'P1D'</span><span style="color: #007700">);<br /> foreach (new </span><span style="color: #0000BB">DatePeriod</span><span style="color: #007700">(</span><span style="color: #0000BB">$start</span><span style="color: #007700">, </span><span style="color: #0000BB">$interval</span><span style="color: #007700">, </span><span style="color: #0000BB">$end</span><span style="color: #007700">) as </span><span style="color: #0000BB">$freeTime</span><span style="color: #007700">) {<br /> </span><span style="color: #0000BB">$this</span><span style="color: #007700">-></span><span style="color: #0000BB">free</span><span style="color: #007700">[] = </span><span style="color: #0000BB">$freeTime</span><span style="color: #007700">;<br /> }<br /> }<br /><br /> public function </span><span style="color: #0000BB">bookAppointment</span><span style="color: #007700">(</span><span style="color: #0000BB">DateTime $date</span><span style="color: #007700">, </span><span style="color: #0000BB">$note</span><span style="color: #007700">) {<br /> </span><span style="color: #0000BB">$this</span><span style="color: #007700">-></span><span style="color: #0000BB">booked</span><span style="color: #007700">[] = array(</span><span style="color: #DD0000">'date' </span><span style="color: #007700">=> </span><span style="color: #0000BB">$date</span><span style="color: #007700">-></span><span style="color: #0000BB">modify</span><span style="color: #007700">(</span><span style="color: #DD0000">'midnight'</span><span style="color: #007700">), </span><span style="color: #DD0000">'note' </span><span style="color: #007700">=> </span><span style="color: #0000BB">$note</span><span style="color: #007700">);<br /> }<br /><br /> public function </span><span style="color: #0000BB">checkAvailability</span><span style="color: #007700">() {<br /> return </span><span style="color: #0000BB">array_udiff</span><span style="color: #007700">(</span><span style="color: #0000BB">$this</span><span style="color: #007700">-></span><span style="color: #0000BB">free</span><span style="color: #007700">, </span><span style="color: #0000BB">$this</span><span style="color: #007700">-></span><span style="color: #0000BB">booked</span><span style="color: #007700">, array(</span><span style="color: #0000BB">$this</span><span style="color: #007700">, </span><span style="color: #DD0000">'customCompare'</span><span style="color: #007700">));<br /> }<br /> <br /> public function </span><span style="color: #0000BB">customCompare</span><span style="color: #007700">(</span><span style="color: #0000BB">$free</span><span style="color: #007700">, </span><span style="color: #0000BB">$booked</span><span style="color: #007700">) {<br /> if (</span><span style="color: #0000BB">is_array</span><span style="color: #007700">(</span><span style="color: #0000BB">$free</span><span style="color: #007700">)) </span><span style="color: #0000BB">$a </span><span style="color: #007700">= </span><span style="color: #0000BB">$free</span><span style="color: #007700">[</span><span style="color: #DD0000">'date'</span><span style="color: #007700">];<br /> else </span><span style="color: #0000BB">$a </span><span style="color: #007700">= </span><span style="color: #0000BB">$free</span><span style="color: #007700">;<br /> if (</span><span style="color: #0000BB">is_array</span><span style="color: #007700">(</span><span style="color: #0000BB">$booked</span><span style="color: #007700">)) </span><span style="color: #0000BB">$b </span><span style="color: #007700">= </span><span style="color: #0000BB">$booked</span><span style="color: #007700">[</span><span style="color: #DD0000">'date'</span><span style="color: #007700">];<br /> else </span><span style="color: #0000BB">$b </span><span style="color: #007700">= </span><span style="color: #0000BB">$booked</span><span style="color: #007700">;<br /> if (</span><span style="color: #0000BB">$a </span><span style="color: #007700">== </span><span style="color: #0000BB">$b</span><span style="color: #007700">) {<br /> return </span><span style="color: #0000BB">0</span><span style="color: #007700">;<br /> } elseif (</span><span style="color: #0000BB">$a </span><span style="color: #007700">> </span><span style="color: #0000BB">$b</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 />}<br /><br /></span><span style="color: #FF8000">// Create a calendar for weekly appointments<br /></span><span style="color: #0000BB">$myCalendar </span><span style="color: #007700">= new </span><span style="color: #0000BB">MyCalendar</span><span style="color: #007700">;<br /><br /></span><span style="color: #FF8000">// Book some appointments for this week<br /></span><span style="color: #0000BB">$myCalendar</span><span style="color: #007700">-></span><span style="color: #0000BB">bookAppointment</span><span style="color: #007700">(new </span><span style="color: #0000BB">DateTime</span><span style="color: #007700">(</span><span style="color: #DD0000">'Monday this week'</span><span style="color: #007700">), </span><span style="color: #DD0000">"Cleaning GoogleGuy's apartment."</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$myCalendar</span><span style="color: #007700">-></span><span style="color: #0000BB">bookAppointment</span><span style="color: #007700">(new </span><span style="color: #0000BB">DateTime</span><span style="color: #007700">(</span><span style="color: #DD0000">'Wednesday this week'</span><span style="color: #007700">), </span><span style="color: #DD0000">"Going on a snowboarding trip."</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$myCalendar</span><span style="color: #007700">-></span><span style="color: #0000BB">bookAppointment</span><span style="color: #007700">(new </span><span style="color: #0000BB">DateTime</span><span style="color: #007700">(</span><span style="color: #DD0000">'Friday this week'</span><span style="color: #007700">), </span><span style="color: #DD0000">"Fixing buggy code."</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">// Check availability of days by comparing $booked dates against $free dates<br /></span><span style="color: #007700">echo </span><span style="color: #DD0000">"I'm available on the following days this week...\n\n"</span><span style="color: #007700">;<br />foreach (</span><span style="color: #0000BB">$myCalendar</span><span style="color: #007700">-></span><span style="color: #0000BB">checkAvailability</span><span style="color: #007700">() as </span><span style="color: #0000BB">$free</span><span style="color: #007700">) {<br /> echo </span><span style="color: #0000BB">$free</span><span style="color: #007700">-></span><span style="color: #0000BB">format</span><span style="color: #007700">(</span><span style="color: #DD0000">'l'</span><span style="color: #007700">), </span><span style="color: #DD0000">"\n"</span><span style="color: #007700">; <br />}<br />echo </span><span style="color: #DD0000">"\n\n"</span><span style="color: #007700">;<br />echo </span><span style="color: #DD0000">"I'm busy on the following days this week...\n\n"</span><span style="color: #007700">;<br />foreach (</span><span style="color: #0000BB">$myCalendar</span><span style="color: #007700">-></span><span style="color: #0000BB">booked </span><span style="color: #007700">as </span><span style="color: #0000BB">$booked</span><span style="color: #007700">) {<br /> echo </span><span style="color: #0000BB">$booked</span><span style="color: #007700">[</span><span style="color: #DD0000">'date'</span><span style="color: #007700">]-></span><span style="color: #0000BB">format</span><span style="color: #007700">(</span><span style="color: #DD0000">'l'</span><span style="color: #007700">), </span><span style="color: #DD0000">": "</span><span style="color: #007700">, </span><span style="color: #0000BB">$booked</span><span style="color: #007700">[</span><span style="color: #DD0000">'note'</span><span style="color: #007700">], </span><span style="color: #DD0000">"\n"</span><span style="color: #007700">; <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>
I'm available on the following days this week...
Tuesday
Thursday
I'm busy on the following days this week...
Monday: Cleaning GoogleGuy's apartment.
Wednesday: Going on a snowboarding trip.
Friday: Fixing buggy code.
</pre></div>
</div>
</div>
</p>
</div>
<div class="refsect1 notes" id="refsect1-function.array-udiff-notes">
<h3 class="title">Notes</h3>
<blockquote class="note"><p><strong class="note">Note</strong>:
<span class="simpara">
Please note that this function only checks one dimension of a n-dimensional
array. Of course you can check deeper dimensions by using
<em>array_udiff($array1[0], $array2[0], "data_compare_func");</em>.
</span>
</p></blockquote>
</div>
<div class="refsect1 seealso" id="refsect1-function.array-udiff-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-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>
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