<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <HTML ><HEAD ><TITLE >strpos</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="String 字符串处理函数" HREF="ref.strings.html"><LINK REL="PREVIOUS" TITLE="strpbrk" HREF="function.strpbrk.html"><LINK REL="NEXT" TITLE="strrchr" HREF="function.strrchr.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.strpbrk.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.strrchr.html" ACCESSKEY="N" >下一页</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="function.strpos" ></A >strpos</H1 ><DIV CLASS="refnamediv" ><A NAME="AEN227962" ></A ><P > (PHP 3, PHP 4, PHP 5)</P >strpos -- Find position of first occurrence of a string </DIV ><DIV CLASS="refsect1" ><A NAME="AEN227965" ></A ><H2 >Description</H2 >int <B CLASS="methodname" >strpos</B > ( string haystack, mixed needle [, int offset] )<BR ></BR ><P > Returns the numeric position of the first occurrence of <CODE CLASS="parameter" >needle</CODE > in the <CODE CLASS="parameter" >haystack</CODE > string. Unlike the <A HREF="function.strrpos.html" ><B CLASS="function" >strrpos()</B ></A > before PHP 5, this function can take a full string as the <CODE CLASS="parameter" >needle</CODE > parameter and the entire string will be used. </P ><P > If <CODE CLASS="parameter" >needle</CODE > is not found, <B CLASS="function" >strpos()</B > will return <A HREF="language.types.boolean.html" ><B CLASS="type" >boolean</B ></A > <TT CLASS="constant" ><B >FALSE</B ></TT >. </P ><DIV CLASS="warning" ><P ></P ><TABLE CLASS="warning" BORDER="1" WIDTH="100%" ><TR ><TD ALIGN="CENTER" ><B >警告</B ></TD ></TR ><TR ><TD ALIGN="LEFT" ><P >本函数可能返回布尔值 <TT CLASS="constant" ><B >FALSE</B ></TT >,但也可能返回一个与 <TT CLASS="constant" ><B >FALSE</B ></TT > 等值的非布尔值,例如 <TT CLASS="literal" >0</TT > 或者 ""。请参阅<A HREF="language.types.boolean.html" >布尔类型</A >章节以获取更多信息。应使用 <A HREF="language.operators.comparison.html" >=== 运算符</A >来测试本函数的返回值。</P ></TD ></TR ></TABLE ></DIV ><DIV CLASS="note" ><BLOCKQUOTE CLASS="note" ><P ><B >注意: </B >本函数可安全用于二进制对象。</P ></BLOCKQUOTE ></DIV ><P > <TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" CLASS="EXAMPLE" ><TR ><TD ><DIV CLASS="example" ><A NAME="AEN227999" ></A ><P ><B >例 1. <B CLASS="function" >strpos()</B > examples</B ></P ><TABLE BORDER="0" BGCOLOR="#E0E0E0" CELLPADDING="5" ><TR ><TD ><code><font color="#000000"> <font color="#0000BB"><?php<br />$mystring </font><font color="#007700">= </font><font color="#DD0000">'abc'</font><font color="#007700">;<br /></font><font color="#0000BB">$findme </font><font color="#007700">= </font><font color="#DD0000">'a'</font><font color="#007700">;<br /></font><font color="#0000BB">$pos </font><font color="#007700">= </font><font color="#0000BB">strpos</font><font color="#007700">(</font><font color="#0000BB">$mystring</font><font color="#007700">, </font><font color="#0000BB">$findme</font><font color="#007700">);<br /><br /></font><font color="#FF8000">// Note our use of ===. Simply == would not work as expected<br />// because the position of 'a' was the 0th (first) character.<br /></font><font color="#007700">if (</font><font color="#0000BB">$pos </font><font color="#007700">=== </font><font color="#0000BB">false</font><font color="#007700">) {<br /> echo </font><font color="#DD0000">"The string '$findme' was not found in the string '$mystring'"</font><font color="#007700">;<br />} else {<br /> echo </font><font color="#DD0000">"The string '$findme' was found in the string '$mystring'"</font><font color="#007700">;<br /> echo </font><font color="#DD0000">" and exists at position $pos"</font><font color="#007700">;<br />}<br /><br /></font><font color="#FF8000">// We can search for the character, ignoring anything before the offset<br /></font><font color="#0000BB">$newstring </font><font color="#007700">= </font><font color="#DD0000">'abcdef abcdef'</font><font color="#007700">;<br /></font><font color="#0000BB">$pos </font><font color="#007700">= </font><font color="#0000BB">strpos</font><font color="#007700">(</font><font color="#0000BB">$newstring</font><font color="#007700">, </font><font color="#DD0000">'a'</font><font color="#007700">, </font><font color="#0000BB">1</font><font color="#007700">); </font><font color="#FF8000">// $pos = 7, not 0<br /></font><font color="#0000BB">?></font> </font> </code></TD ></TR ></TABLE ></DIV ></TD ></TR ></TABLE > </P ><P > If <CODE CLASS="parameter" >needle</CODE > is not a string, it is converted to an integer and applied as the ordinal value of a character. </P ><P > The optional <CODE CLASS="parameter" >offset</CODE > parameter allows you to specify which character in <CODE CLASS="parameter" >haystack</CODE > to start searching. The position returned is still relative to the beginning of <CODE CLASS="parameter" >haystack</CODE >. </P ><P > See also <A HREF="function.strrpos.html" ><B CLASS="function" >strrpos()</B ></A >, <A HREF="function.stripos.html" ><B CLASS="function" >stripos()</B ></A >, <A HREF="function.strripos.html" ><B CLASS="function" >strripos()</B ></A >, <A HREF="function.strrchr.html" ><B CLASS="function" >strrchr()</B ></A >, <A HREF="function.substr.html" ><B CLASS="function" >substr()</B ></A >, <A HREF="function.stristr.html" ><B CLASS="function" >stristr()</B ></A >, and <A HREF="function.strstr.html" ><B CLASS="function" >strstr()</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.strpbrk.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.strrchr.html" ACCESSKEY="N" >下一页</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >strpbrk</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="ref.strings.html" ACCESSKEY="U" >上一级</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >strrchr</TD ></TR ></TABLE ></DIV ></BODY ></HTML >