<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <HTML ><HEAD ><TITLE >method_exists</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK REL="HOME" TITLE="PHP 手册" HREF="index.html"><LINK REL="UP" TITLE="Classes/Objects 类/对象函数" HREF="ref.classobj.html"><LINK REL="PREVIOUS" TITLE="is_subclass_of" HREF="function.is-subclass-of.html"><LINK REL="NEXT" TITLE="property_exists" HREF="function.property-exists.html"><META HTTP-EQUIV="Content-type" CONTENT="text/html; charset=UTF-8"></HEAD ><BODY CLASS="refentry" BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#0000FF" VLINK="#840084" ALINK="#0000FF" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >PHP 手册</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="function.is-subclass-of.html" ACCESSKEY="P" >上一页</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="function.property-exists.html" ACCESSKEY="N" >下一页</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="function.method-exists" ></A >method_exists</H1 ><DIV CLASS="refnamediv" ><A NAME="AEN17148" ></A ><P > (PHP 4, PHP 5)</P >method_exists -- 检查类的方法是否存在</DIV ><DIV CLASS="refsect1" ><A NAME="AEN17151" ></A ><H2 >说明</H2 >bool <B CLASS="methodname" >method_exists</B > ( object object, string method_name )<BR ></BR ><P > 如果 <CODE CLASS="parameter" >method_name</CODE > 所指的方法在 <CODE CLASS="parameter" >object</CODE > 所指的对象类中已定义,则返回 <TT CLASS="constant" ><B >TRUE</B ></TT >,否则返回 <TT CLASS="constant" ><B >FALSE</B ></TT >。 </P ><P > <TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" CLASS="EXAMPLE" ><TR ><TD ><DIV CLASS="example" ><A NAME="AEN17168" ></A ><P ><B >例 1. <B CLASS="function" >method_exists()</B > 例子</B ></P ><TABLE BORDER="0" BGCOLOR="#E0E0E0" CELLPADDING="5" ><TR ><TD ><code><font color="#000000"> <font color="#0000BB"><?php<br />$directory </font><font color="#007700">= new </font><font color="#0000BB">Directory</font><font color="#007700">(</font><font color="#DD0000">'.'</font><font color="#007700">);<br /></font><font color="#0000BB">var_dump</font><font color="#007700">(</font><font color="#0000BB">method_exists</font><font color="#007700">(</font><font color="#0000BB">$directory</font><font color="#007700">,</font><font color="#DD0000">'read'</font><font color="#007700">));<br /></font><font color="#0000BB">?></font> </font> </code></TD ></TR ></TABLE ><P >上例将输出:</P ><TABLE BORDER="0" BGCOLOR="#E0E0E0" CELLPADDING="5" ><TR ><TD ><PRE CLASS="screen" >bool(true)</PRE ></TD ></TR ></TABLE ></DIV ></TD ></TR ></TABLE > </P ><P > 参见 <A HREF="function.function-exists.html" ><B CLASS="function" >function_exists()</B ></A > 和 <A HREF="function.is-callable.html" ><B CLASS="function" >is_callable()</B ></A >。 </P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="function.is-subclass-of.html" ACCESSKEY="P" >上一页</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >起始页</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="function.property-exists.html" ACCESSKEY="N" >下一页</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >is_subclass_of</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="ref.classobj.html" ACCESSKEY="U" >上一级</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >property_exists</TD ></TR ></TABLE ></DIV ></BODY ></HTML >