function.interface-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 interface has been defined</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="function.get-parent-class.html">get_parent_class</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.is-a.html">is_a</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.interface-exists" class="refentry"> <div class="refnamediv"> <h1 class="refname">interface_exists</h1> <p class="verinfo">(PHP 5 >= 5.0.2)</p><p class="refpurpose"><span class="refname">interface_exists</span> — <span class="dc-title">Checks if the interface has been defined</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>interface_exists</b></b></span> ( <span class="methodparam"><span class="type">string</span> <tt class="parameter">$interface_name</tt></span> [, <span class="methodparam"><span class="type">bool</span> <tt class="parameter">$autoload</tt></span> ] )</div> <p class="para rdfs-comment"> Checks if the given interface has been defined. </p> </div> <div class="refsect1 parameters"> <h3 class="title">Parameters</h3> <p class="para"> <dl> <dt> <span class="term"><i><tt class="parameter">interface_name</tt></i></span> <dd> <p class="para"> The interface name </p> </dd> </dt> <dt> <span class="term"><i><tt class="parameter">autoload</tt></i></span> <dd> <p class="para"> Whether to call <a href="language.oop5.autoload.html" class="link">__autoload</a> or not by default </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 interface given by <i><tt class="parameter">interface_name</tt></i> has been defined, <b><tt>FALSE</tt></b> otherwise. </p> </div> <div class="refsect1 examples"> <h3 class="title">Examples</h3> <p class="para"> <div class="example"> <p><b>Example #1 <b>interface_exists()</b> example</b></p> <div class="example-contents"><div class="phpcode"><code><span style="color: #000000"><span style="color: #0000BB"><?php<br /></span><span style="color: #FF8000">// Check the interface exists before trying to use it<br /></span><span style="color: #007700">if (</span><span style="color: #0000BB">interface_exists</span><span style="color: #007700">(</span><span style="color: #DD0000">'MyInterface'</span><span style="color: #007700">)) {<br /> class </span><span style="color: #0000BB">MyClass </span><span style="color: #007700">implements </span><span style="color: #0000BB">MyInterface<br /> </span><span style="color: #007700">{<br /> </span><span style="color: #FF8000">// Methods<br /> </span><span style="color: #007700">}<br />}<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.class-exists.html" class="function" rel="rdfs-seeAlso">class_exists()</a></li> </ul> </p> </div></div><hr /><div style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="function.get-parent-class.html">get_parent_class</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.is-a.html">is_a</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></body></html>⌨️ 快捷键说明
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