<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <HTML ><HEAD ><TITLE >iconv_substr</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="iconv Functions" HREF="ref.iconv.html"><LINK REL="PREVIOUS" TITLE="iconv_strrpos" HREF="function.iconv-strrpos.html"><LINK REL="NEXT" TITLE="iconv" HREF="function.iconv.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.iconv-strrpos.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.iconv.html" ACCESSKEY="N" >下一页</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="function.iconv-substr" ></A >iconv_substr</H1 ><DIV CLASS="refnamediv" ><A NAME="AEN84993" ></A ><P > (PHP 5)</P >iconv_substr -- Cut out part of a string</DIV ><DIV CLASS="refsect1" ><A NAME="AEN84996" ></A ><H2 >说明</H2 >string <B CLASS="methodname" >iconv_substr</B > ( string str, int offset [, int length [, string charset]] )<BR ></BR ><P > Cuts a portion of <CODE CLASS="parameter" >str</CODE > specified by the <CODE CLASS="parameter" >offset</CODE > and <CODE CLASS="parameter" >length</CODE > parameters. </P ></DIV ><DIV CLASS="refsect1" ><A NAME="AEN85017" ></A ><H2 >参数</H2 ><P > <P ></P ><DIV CLASS="variablelist" ><DL ><DT ><CODE CLASS="parameter" >str</CODE ></DT ><DD ><P > The original string. </P ></DD ><DT ><CODE CLASS="parameter" >offset</CODE ></DT ><DD ><P > If <CODE CLASS="parameter" >offset</CODE > is non-negative, <B CLASS="function" >iconv_substr()</B > cuts the portion out of <CODE CLASS="parameter" >str</CODE > beginning at <CODE CLASS="parameter" >offset</CODE >'th character, counting from zero. </P ><P > If <CODE CLASS="parameter" >offset</CODE > is negative, <B CLASS="function" >iconv_substr()</B > cuts out the portion beginning at the position, <CODE CLASS="parameter" >offset</CODE > characters away from the end of <CODE CLASS="parameter" >str</CODE >. </P ></DD ><DT ><CODE CLASS="parameter" >length</CODE ></DT ><DD ><P > If <CODE CLASS="parameter" >length</CODE > is given and is positive, the return value will contain at most <CODE CLASS="parameter" >length</CODE > characters of the portion that begins at <CODE CLASS="parameter" >offset</CODE > (depending on the length of <CODE CLASS="parameter" >string</CODE >). </P ><P > If negative <CODE CLASS="parameter" >length</CODE > is passed, <B CLASS="function" >iconv_substr()</B > cuts the portion out of <CODE CLASS="parameter" >str</CODE > from the <CODE CLASS="parameter" >offset</CODE >'th character up to the character that is <CODE CLASS="parameter" >length</CODE > characters away from the end of the string. In case <CODE CLASS="parameter" >offset</CODE > is also negative, the start position is calculated beforehand according to the rule explained above. </P ></DD ><DT ><CODE CLASS="parameter" >charset</CODE ></DT ><DD ><P > If <CODE CLASS="parameter" >charset</CODE > parameter is omitted, <CODE CLASS="parameter" >string</CODE > are assumed to be encoded in <A HREF="ref.iconv.html#iconv.configuration" >iconv.internal_encoding</A >. </P ><P > Note that <CODE CLASS="parameter" >offset</CODE > and <CODE CLASS="parameter" >length</CODE > parameters are always deemed to represent offsets that are calculated on the basis of the character set determined by <CODE CLASS="parameter" >charset</CODE >, whilst the counterpart <A HREF="function.substr.html" ><B CLASS="function" >substr()</B ></A > always takes these for byte offsets. </P ></DD ></DL ></DIV > </P ></DIV ><DIV CLASS="refsect1" ><A NAME="AEN85069" ></A ><H2 >返回值</H2 ><P > Returns the portion of <CODE CLASS="parameter" >str</CODE > specified by the <CODE CLASS="parameter" >offset</CODE > and <CODE CLASS="parameter" >length</CODE > parameters. </P ><P > If <CODE CLASS="parameter" >str</CODE > is shorter than <CODE CLASS="parameter" >offset</CODE > characters long, <TT CLASS="constant" ><B >FALSE</B ></TT > will be returned. </P ></DIV ><DIV CLASS="refsect1" ><A NAME="AEN85079" ></A ><H2 >参见</H2 ><P > <P ></P ><TABLE BORDER="0" ><TBODY ><TR ><TD ><A HREF="function.substr.html" ><B CLASS="function" >substr()</B ></A ></TD ></TR ><TR ><TD ><A HREF="function.mb-substr.html" ><B CLASS="function" >mb_substr()</B ></A ></TD ></TR ><TR ><TD ><A HREF="function.mb-strcut.html" ><B CLASS="function" >mb_strcut()</B ></A ></TD ></TR ></TBODY ></TABLE ><P ></P > </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.iconv-strrpos.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.iconv.html" ACCESSKEY="N" >下一页</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >iconv_strrpos</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="ref.iconv.html" ACCESSKEY="U" >上一级</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >iconv</TD ></TR ></TABLE ></DIV ></BODY ></HTML >