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<title>Count all elements in an array, or something in an object</title>
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<div class="refnamediv">
<h1 class="refname">count</h1>
<p class="verinfo">(PHP 4, PHP 5)</p><p class="refpurpose"><span class="refname">count</span> — <span class="dc-title">Count all elements in an array, or something in an object</span></p>
</div>
<div class="refsect1 description" id="refsect1-function.count-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type">int</span> <span class="methodname"><strong>count</strong></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">$array_or_countable</code></span>
[, <span class="methodparam"><span class="type">int</span> <code class="parameter">$mode</code><span class="initializer"> = COUNT_NORMAL</span></span>
] )</div>
<p class="para rdfs-comment">
Counts all elements in an array, or something in an object.
</p>
<p class="para">
For objects, if you have
<a href="ref.spl.html" class="link">SPL</a> installed, you can hook into
<span class="function"><strong>count()</strong></span> by implementing interface
<a href="class.countable.html" class="classname">Countable</a>. The interface has exactly one method,
<span class="methodname"><a href="countable.count.html" class="methodname">Countable::count()</a></span>, which returns the return value for the
<span class="function"><strong>count()</strong></span> function.
</p>
<p class="para">
Please see the <a href="language.types.array.html" class="link">Array</a>
section of the manual for a detailed explanation of how arrays
are implemented and used in PHP.
</p>
</div>
<div class="refsect1 parameters" id="refsect1-function.count-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<span class="term"><em><code class="parameter">array_or_countable</code></em></span>
<dd>
<p class="para">
An array or <a href="class.countable.html" class="classname">Countable</a> object.
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">mode</code></em></span>
<dd>
<p class="para">
If the optional <em><code class="parameter">mode</code></em> parameter is set to
<strong><code>COUNT_RECURSIVE</code></strong> (or 1), <span class="function"><strong>count()</strong></span>
will recursively count the array. This is particularly useful for
counting all the elements of a multidimensional array.
</p>
<div class="caution"><strong class="caution">Caution</strong>
<p class="para">
<span class="function"><strong>count()</strong></span> can detect recursion to avoid an infinite
loop, but will emit an <strong><code>E_WARNING</code></strong> every time it
does (in case the array contains itself more than once) and return a
count higher than may be expected.
</p>
</div>
</dd>
</dt>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.count-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
Returns the number of elements in <em><code class="parameter">array_or_countable</code></em>.
If the parameter is not an array or not an object with
implemented <a href="class.countable.html" class="classname">Countable</a> interface,
<em>1</em> will be returned.
There is one exception, if <em><code class="parameter">array_or_countable</code></em> is <strong><code>NULL</code></strong>,
<em>0</em> will be returned.
</p>
<div class="caution"><strong class="caution">Caution</strong>
<p class="para">
<span class="function"><strong>count()</strong></span> may return 0 for a variable that isn't set,
but it may also return 0 for a variable that has been initialized with an
empty array. Use <span class="function"><a href="function.isset.html" class="function">isset()</a></span> to test if a variable is set.
</p>
</div>
</div>
<div class="refsect1 changelog" id="refsect1-function.count-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 optional <em><code class="parameter">mode</code></em> parameter was added.
</td>
</tr>
</tbody>
</table>
</p>
</div>
<div class="refsect1 examples" id="refsect1-function.count-examples">
<h3 class="title">Examples</h3>
<p class="para">
<div class="example" id="example-5006">
<p><strong>Example #1 <span class="function"><strong>count()</strong></span> example</strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br />$a</span><span style="color: #007700">[</span><span style="color: #0000BB">0</span><span style="color: #007700">] = </span><span style="color: #0000BB">1</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$a</span><span style="color: #007700">[</span><span style="color: #0000BB">1</span><span style="color: #007700">] = </span><span style="color: #0000BB">3</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$a</span><span style="color: #007700">[</span><span style="color: #0000BB">2</span><span style="color: #007700">] = </span><span style="color: #0000BB">5</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$result </span><span style="color: #007700">= </span><span style="color: #0000BB">count</span><span style="color: #007700">(</span><span style="color: #0000BB">$a</span><span style="color: #007700">);<br /></span><span style="color: #FF8000">// $result == 3<br /><br /></span><span style="color: #0000BB">$b</span><span style="color: #007700">[</span><span style="color: #0000BB">0</span><span style="color: #007700">] = </span><span style="color: #0000BB">7</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$b</span><span style="color: #007700">[</span><span style="color: #0000BB">5</span><span style="color: #007700">] = </span><span style="color: #0000BB">9</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$b</span><span style="color: #007700">[</span><span style="color: #0000BB">10</span><span style="color: #007700">] = </span><span style="color: #0000BB">11</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$result </span><span style="color: #007700">= </span><span style="color: #0000BB">count</span><span style="color: #007700">(</span><span style="color: #0000BB">$b</span><span style="color: #007700">);<br /></span><span style="color: #FF8000">// $result == 3<br /><br /></span><span style="color: #0000BB">$result </span><span style="color: #007700">= </span><span style="color: #0000BB">count</span><span style="color: #007700">(</span><span style="color: #0000BB">null</span><span style="color: #007700">);<br /></span><span style="color: #FF8000">// $result == 0<br /><br /></span><span style="color: #0000BB">$result </span><span style="color: #007700">= </span><span style="color: #0000BB">count</span><span style="color: #007700">(</span><span style="color: #0000BB">false</span><span style="color: #007700">);<br /></span><span style="color: #FF8000">// $result == 1<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
</div>
</p>
<p class="para">
<div class="example" id="example-5007">
<p><strong>Example #2 Recursive <span class="function"><strong>count()</strong></span> example</strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br />$food </span><span style="color: #007700">= array(</span><span style="color: #DD0000">'fruits' </span><span style="color: #007700">=> array(</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: #DD0000">'veggie' </span><span style="color: #007700">=> array(</span><span style="color: #DD0000">'carrot'</span><span style="color: #007700">, </span><span style="color: #DD0000">'collard'</span><span style="color: #007700">, </span><span style="color: #DD0000">'pea'</span><span style="color: #007700">));<br /><br /></span><span style="color: #FF8000">// recursive count<br /></span><span style="color: #007700">echo </span><span style="color: #0000BB">count</span><span style="color: #007700">(</span><span style="color: #0000BB">$food</span><span style="color: #007700">, </span><span style="color: #0000BB">COUNT_RECURSIVE</span><span style="color: #007700">); </span><span style="color: #FF8000">// output 8<br /><br />// normal count<br /></span><span style="color: #007700">echo </span><span style="color: #0000BB">count</span><span style="color: #007700">(</span><span style="color: #0000BB">$food</span><span style="color: #007700">); </span><span style="color: #FF8000">// output 2<br /><br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
</div>
</p>
</div>
<div class="refsect1 seealso" id="refsect1-function.count-seealso">
<h3 class="title">See Also</h3>
<p class="para">
<ul class="simplelist">
<li class="member"> <span class="function"><a href="function.is-array.html" class="function" rel="rdfs-seeAlso">is_array()</a> - Finds whether a variable is an array</span></li>
<li class="member"> <span class="function"><a href="function.isset.html" class="function" rel="rdfs-seeAlso">isset()</a> - Determine if a variable is set and is not NULL</span></li>
<li class="member"> <span class="function"><a href="function.strlen.html" class="function" rel="rdfs-seeAlso">strlen()</a> - Get string length</span></li>
</ul>
</p>
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