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<title>Checks if the object is of this class or has this class as one of its parents</title>
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<div class="refnamediv">
<h1 class="refname">is_a</h1>
<p class="verinfo">(PHP 4 >= 4.2.0, PHP 5)</p><p class="refpurpose"><span class="refname">is_a</span> — <span class="dc-title">Checks if the object is of this class or has this class as one of its parents</span></p>
</div>
<div class="refsect1 description" id="refsect1-function.is-a-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type">bool</span> <span class="methodname"><strong>is_a</strong></span>
( <span class="methodparam"><span class="type">object</span> <code class="parameter">$object</code></span>
, <span class="methodparam"><span class="type">string</span> <code class="parameter">$class_name</code></span>
[, <span class="methodparam"><span class="type">bool</span> <code class="parameter">$allow_string</code><span class="initializer"> = <strong><code>FALSE</code></strong></span></span>
] )</div>
<p class="para rdfs-comment">
Checks if the given <em><code class="parameter">object</code></em> is of this class or has
this class as one of its parents.
</p>
</div>
<div class="refsect1 parameters" id="refsect1-function.is-a-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<span class="term"><em><code class="parameter">object</code></em></span>
<dd>
<p class="para">
The tested object
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">class_name</code></em></span>
<dd>
<p class="para">
The class name
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">allow_string</code></em></span>
<dd>
<p class="para">
If this parameter set to <strong><code>FALSE</code></strong>, string class name as <em><code class="parameter">object</code></em>
is not allowed. This also prevents from calling autoloader if the class doesn't exist.
</p>
</dd>
</dt>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.is-a-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
Returns <strong><code>TRUE</code></strong> if the object is of this class or has this class as one of
its parents, <strong><code>FALSE</code></strong> otherwise.
</p>
</div>
<div class="refsect1 changelog" id="refsect1-function.is-a-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>5.3.9</td>
<td>
Added <em><code class="parameter">allow_string</code></em> parameter
</td>
</tr>
<tr>
<td>5.3.0</td>
<td>
This function is no longer deprecated, and will therefore
no longer throw <strong><code>E_STRICT</code></strong> warnings.
</td>
</tr>
<tr>
<td>5.0.0</td>
<td>
This function became deprecated in favour of the
<a href="language.operators.type.html" class="link">instanceof</a>
operator. Calling this function will result in an
<strong><code>E_STRICT</code></strong> warning.
</td>
</tr>
</tbody>
</table>
</p>
</div>
<div class="refsect1 examples" id="refsect1-function.is-a-examples">
<h3 class="title">Examples</h3>
<p class="para">
<div class="example" id="example-5058">
<p><strong>Example #1 <span class="function"><strong>is_a()</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: #FF8000">// define a class<br /></span><span style="color: #007700">class </span><span style="color: #0000BB">WidgetFactory<br /></span><span style="color: #007700">{<br /> var </span><span style="color: #0000BB">$oink </span><span style="color: #007700">= </span><span style="color: #DD0000">'moo'</span><span style="color: #007700">;<br />}<br /><br /></span><span style="color: #FF8000">// create a new object<br /></span><span style="color: #0000BB">$WF </span><span style="color: #007700">= new </span><span style="color: #0000BB">WidgetFactory</span><span style="color: #007700">();<br /><br />if (</span><span style="color: #0000BB">is_a</span><span style="color: #007700">(</span><span style="color: #0000BB">$WF</span><span style="color: #007700">, </span><span style="color: #DD0000">'WidgetFactory'</span><span style="color: #007700">)) {<br /> echo </span><span style="color: #DD0000">"yes, \$WF is still a WidgetFactory\n"</span><span style="color: #007700">;<br />}<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
</div>
<div class="example" id="example-5059">
<p><strong>Example #2 Using the <em class="emphasis">instanceof</em> operator in PHP 5</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">if (</span><span style="color: #0000BB">$WF </span><span style="color: #007700">instanceof </span><span style="color: #0000BB">WidgetFactory</span><span style="color: #007700">) {<br /> echo </span><span style="color: #DD0000">'Yes, $WF is a WidgetFactory'</span><span style="color: #007700">;<br />}<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
</div>
</p>
</div>
<div class="refsect1 seealso" id="refsect1-function.is-a-seealso">
<h3 class="title">See Also</h3>
<p class="para">
<ul class="simplelist">
<li class="member"> <span class="function"><a href="function.get-class.html" class="function" rel="rdfs-seeAlso">get_class()</a> - Returns the name of the class of an object</span></li>
<li class="member"> <span class="function"><a href="function.get-parent-class.html" class="function" rel="rdfs-seeAlso">get_parent_class()</a> - Retrieves the parent class name for object or class</span></li>
<li class="member"> <span class="function"><a href="function.is-subclass-of.html" class="function" rel="rdfs-seeAlso">is_subclass_of()</a> - Checks if the object has this class as one of its parents</span></li>
</ul>
</p>
</div>
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