<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <HTML ><HEAD ><TITLE >count_chars</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="convert_uuencode" HREF="function.convert-uuencode.html"><LINK REL="NEXT" TITLE="crc32" HREF="function.crc32.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.convert-uuencode.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.crc32.html" ACCESSKEY="N" >下一页</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="function.count-chars" ></A >count_chars</H1 ><DIV CLASS="refnamediv" ><A NAME="AEN224760" ></A ><P > (PHP 4, PHP 5)</P >count_chars -- 返回字符串所用字符的信息</DIV ><DIV CLASS="refsect1" ><A NAME="AEN224763" ></A ><H2 >说明</H2 >mixed <B CLASS="methodname" >count_chars</B > ( string string [, int mode] )<BR ></BR ><P > 统计 <CODE CLASS="parameter" >string</CODE > 中每个字节值(0..255)出现的次数,使用多种模式返回结果。可选参数 <CODE CLASS="parameter" >mode</CODE > 默认值为 0。根据不同的 <CODE CLASS="parameter" >mode</CODE >,<B CLASS="function" >count_chars()</B > 返回下列不同的结果: <P ></P ><UL ><LI ><P > 0 - 以所有的每个字节值作为键名,出现次数作为值的数组。 </P ></LI ><LI ><P > 1 - 与 0 相同,但只列出出现次数大于零的字节值。 </P ></LI ><LI ><P > 2 - 与 0 相同,但只列出出现次数等于零的字节值。 </P ></LI ><LI ><P > 3 - 返回由所有使用了的字节值组成的字符串。 </P ></LI ><LI ><P > 4 - 返回由所有未使用的字节值组成的字符串。 </P ></LI ></UL > </P ><P > <TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" CLASS="EXAMPLE" ><TR ><TD ><DIV CLASS="example" ><A NAME="AEN224791" ></A ><P ><B >例 1. <B CLASS="function" >count_chars()</B > 示例</B ></P ><TABLE BORDER="0" BGCOLOR="#E0E0E0" CELLPADDING="5" ><TR ><TD ><code><font color="#000000"> <font color="#0000BB"><?php<br />$data </font><font color="#007700">= </font><font color="#DD0000">"Two Ts and one F."</font><font color="#007700">;<br /><br />foreach (</font><font color="#0000BB">count_chars</font><font color="#007700">(</font><font color="#0000BB">$data</font><font color="#007700">, </font><font color="#0000BB">1</font><font color="#007700">) as </font><font color="#0000BB">$i </font><font color="#007700">=> </font><font color="#0000BB">$val</font><font color="#007700">) {<br /> echo </font><font color="#DD0000">"There were $val instance(s) of </font><font color="#007700">\"</font><font color="#DD0000">" </font><font color="#007700">, </font><font color="#0000BB">chr</font><font color="#007700">(</font><font color="#0000BB">$i</font><font color="#007700">) , </font><font color="#DD0000">"\" in the string.\n"</font><font color="#007700">;<br />}<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" >There were 4 instance(s) of " " in the string. There were 1 instance(s) of "." in the string. There were 1 instance(s) of "F" in the string. There were 2 instance(s) of "T" in the string. There were 1 instance(s) of "a" in the string. There were 1 instance(s) of "d" in the string. There were 1 instance(s) of "e" in the string. There were 2 instance(s) of "n" in the string. There were 2 instance(s) of "o" in the string. There were 1 instance(s) of "s" in the string. There were 1 instance(s) of "w" in the string.</PRE ></TD ></TR ></TABLE ></DIV ></TD ></TR ></TABLE > </P ><P > 参见 <A HREF="function.strpos.html" ><B CLASS="function" >strpos()</B ></A > 和 <A HREF="function.substr-count.html" ><B CLASS="function" >substr_count()</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.convert-uuencode.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.crc32.html" ACCESSKEY="N" >下一页</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >convert_uuencode</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" >crc32</TD ></TR ></TABLE ></DIV ></BODY ></HTML >