function.property-exists.html
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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html> <head> <title>Checks if the object or class has a property</title> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> </head> <body><div style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="ref.classobj.html">Classes/Object Functions</a></div> <div class="next" style="text-align: right; float: right;"><a href="book.classkit.html">Classkit</a></div> <div class="up"><a href="ref.classobj.html">Classes/Object Functions</a></div> <div class="home"><a href="index.html">PHP Manual</a></div></div><hr /><div id="function.property-exists" class="refentry"> <div class="refnamediv"> <h1 class="refname">property_exists</h1> <p class="verinfo">(PHP 5 >= 5.1.0)</p><p class="refpurpose"><span class="refname">property_exists</span> — <span class="dc-title"> Checks if the object or class has a property </span></p> </div> <div class="refsect1 description"> <h3 class="title">Description</h3> <div class="methodsynopsis dc-description"> <span class="type">bool</span> <span class="methodname"><b><b>property_exists</b></b></span> ( <span class="methodparam"><span class="type"><a href="language.pseudo-types.html#language.types.mixed" class="type mixed">mixed</a></span> <tt class="parameter">$class</tt></span> , <span class="methodparam"><span class="type">string</span> <tt class="parameter">$property</tt></span> )</div> <p class="para rdfs-comment"> This function checks if the given <i><tt class="parameter">property</tt></i> exists in the specified class. </p> <blockquote><p><b class="note">Note</b>: As opposed with <a href="function.isset.html" class="function">isset()</a>, <b>property_exists()</b> returns <b><tt>TRUE</tt></b> even if the property has the value <b><tt>NULL</tt></b>. <br /> </p></blockquote> </div> <div class="refsect1 parameters"> <h3 class="title">Parameters</h3> <p class="para"> <dl> <dt> <span class="term"><i><tt class="parameter">class</tt></i></span> <dd> <p class="para"> The class name or an object of the class to test for </p> </dd> </dt> <dt> <span class="term"><i><tt class="parameter">property</tt></i></span> <dd> <p class="para"> The name of the property </p> </dd> </dt> </dl> </p> </div> <div class="refsect1 returnvalues"> <h3 class="title">Return Values</h3> <p class="para"> Returns <b><tt>TRUE</tt></b> if the property exists, <b><tt>FALSE</tt></b> if it doesn't exist or <b><tt>NULL</tt></b> in case of an error. </p> </div> <div class="refsect1 changelog"> <h3 class="title">ChangeLog</h3> <p class="para"> <table class="informaltable"> <colgroup> <thead valign="middle"> <tr valign="middle"> <th colspan="1">Version</th> <th colspan="1">Description</th> </tr> </thead> <tbody valign="middle" class="tbody"> <tr valign="middle"> <td colspan="1" rowspan="1" align="left">5.3.0</td> <td colspan="1" rowspan="1" align="left"> This function checks the existence of a property independent of accessibility. </td> </tr> </tbody> </colgroup> </table> </p> </div> <div class="refsect1 examples"> <h3 class="title">Examples</h3> <p class="para"> <div class="example"> <p><b>Example #1 A <b>property_exists()</b> example</b></p> <div class="example-contents"><div class="phpcode"><code><span style="color: #000000"><span style="color: #0000BB"><?php<br /><br /></span><span style="color: #007700">class </span><span style="color: #0000BB">myClass </span><span style="color: #007700">{<br /> public </span><span style="color: #0000BB">$mine</span><span style="color: #007700">;<br /> private </span><span style="color: #0000BB">$xpto</span><span style="color: #007700">;<br /> static protected </span><span style="color: #0000BB">$test</span><span style="color: #007700">;<br /><br /> static function </span><span style="color: #0000BB">test</span><span style="color: #007700">() {<br /> </span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">property_exists</span><span style="color: #007700">(</span><span style="color: #DD0000">'myClass'</span><span style="color: #007700">, </span><span style="color: #DD0000">'xpto'</span><span style="color: #007700">)); </span><span style="color: #FF8000">//true<br /> </span><span style="color: #007700">}<br />}<br /><br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">property_exists</span><span style="color: #007700">(</span><span style="color: #DD0000">'myClass'</span><span style="color: #007700">, </span><span style="color: #DD0000">'mine'</span><span style="color: #007700">)); </span><span style="color: #FF8000">//true<br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">property_exists</span><span style="color: #007700">(new </span><span style="color: #0000BB">myClass</span><span style="color: #007700">, </span><span style="color: #DD0000">'mine'</span><span style="color: #007700">)); </span><span style="color: #FF8000">//true<br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">property_exists</span><span style="color: #007700">(</span><span style="color: #DD0000">'myClass'</span><span style="color: #007700">, </span><span style="color: #DD0000">'xpto'</span><span style="color: #007700">)); </span><span style="color: #FF8000">//true, as of PHP 5.3.0<br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">property_exists</span><span style="color: #007700">(</span><span style="color: #DD0000">'myClass'</span><span style="color: #007700">, </span><span style="color: #DD0000">'bar'</span><span style="color: #007700">)); </span><span style="color: #FF8000">//false<br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">property_exists</span><span style="color: #007700">(</span><span style="color: #DD0000">'myClass'</span><span style="color: #007700">, </span><span style="color: #DD0000">'test'</span><span style="color: #007700">)); </span><span style="color: #FF8000">//true, as of PHP 5.3.0<br /></span><span style="color: #0000BB">myClass</span><span style="color: #007700">::</span><span style="color: #0000BB">test</span><span style="color: #007700">();<br /><br /></span><span style="color: #0000BB">?></span></span></code></div> </div> </div> </p> </div> <div class="refsect1 seealso"> <h3 class="title">See Also</h3> <p class="para"> <ul class="simplelist"> <li class="member"><a href="function.method-exists.html" class="function" rel="rdfs-seeAlso">method_exists()</a></li> </ul> </p> </div></div><hr /><div style="text-align: center;"> <div class="prev" style="text-align: left; 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