<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <HTML ><HEAD ><TITLE >trim</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="substr" HREF="function.substr.html"><LINK REL="NEXT" TITLE="ucfirst" HREF="function.ucfirst.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.substr.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.ucfirst.html" ACCESSKEY="N" >下一页</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="function.trim" ></A >trim</H1 ><DIV CLASS="refnamediv" ><A NAME="AEN228670" ></A ><P > (PHP 3, PHP 4, PHP 5)</P >trim -- Strip whitespace (or other characters) from the beginning and end of a string</DIV ><DIV CLASS="refsect1" ><A NAME="AEN228673" ></A ><H2 >说明</H2 >string <B CLASS="methodname" >trim</B > ( string str [, string charlist] )<BR ></BR ><P > This function returns a string with whitespace stripped from the beginning and end of <CODE CLASS="parameter" >str</CODE >. Without the second parameter, <B CLASS="function" >trim()</B > will strip these characters: <P ></P ><UL ><LI ><P > " " (<ACRONYM CLASS="acronym" >ASCII</ACRONYM > <TT CLASS="literal" >32</TT > (<TT CLASS="literal" >0x20</TT >)), an ordinary space. </P ></LI ><LI ><P > "\t" (<ACRONYM CLASS="acronym" >ASCII</ACRONYM > <TT CLASS="literal" >9</TT > (<TT CLASS="literal" >0x09</TT >)), a tab. </P ></LI ><LI ><P > "\n" (<ACRONYM CLASS="acronym" >ASCII</ACRONYM > <TT CLASS="literal" >10</TT > (<TT CLASS="literal" >0x0A</TT >)), a new line (line feed). </P ></LI ><LI ><P > "\r" (<ACRONYM CLASS="acronym" >ASCII</ACRONYM > <TT CLASS="literal" >13</TT > (<TT CLASS="literal" >0x0D</TT >)), a carriage return. </P ></LI ><LI ><P > "\0" (<ACRONYM CLASS="acronym" >ASCII</ACRONYM > <TT CLASS="literal" >0</TT > (<TT CLASS="literal" >0x00</TT >)), the <TT CLASS="literal" >NUL</TT >-byte. </P ></LI ><LI ><P > "\x0B" (<ACRONYM CLASS="acronym" >ASCII</ACRONYM > <TT CLASS="literal" >11</TT > (<TT CLASS="literal" >0x0B</TT >)), a vertical tab. </P ></LI ></UL > </P ></DIV ><DIV CLASS="refsect1" ><A NAME="AEN228719" ></A ><H2 >参数</H2 ><P > <P ></P ><DIV CLASS="variablelist" ><DL ><DT ><CODE CLASS="parameter" >str</CODE ></DT ><DD ><P > The <A HREF="language.types.string.html" ><B CLASS="type" >string</B ></A > that will be trimmed. </P ></DD ><DT ><CODE CLASS="parameter" >charlist</CODE ></DT ><DD ><P > Optionally, the stripped characters can also be specified using the <CODE CLASS="parameter" >charlist</CODE > parameter. Simply list all characters that you want to be stripped. With <TT CLASS="literal" >..</TT > you can specify a range of characters. </P ></DD ></DL ></DIV > </P ></DIV ><DIV CLASS="refsect1" ><A NAME="AEN228736" ></A ><H2 >返回值</H2 ><P > The trimmed string. </P ></DIV ><DIV CLASS="refsect1" ><A NAME="AEN228739" ></A ><H2 >更新日志</H2 ><P > <DIV CLASS="informaltable" ><P ></P ><A NAME="AEN228742" ></A ><TABLE BORDER="1" CLASS="CALSTABLE" ><COL><COL><THEAD ><TR ><TH >版本</TH ><TH >说明</TH ></TR ></THEAD ><TBODY ><TR ><TD >4.1.0</TD ><TD > The optional <CODE CLASS="parameter" >charlist</CODE > parameter was added. </TD ></TR ></TBODY ></TABLE ><P ></P ></DIV > </P ></DIV ><DIV CLASS="refsect1" ><A NAME="AEN228753" ></A ><H2 >范例</H2 ><P > <TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" CLASS="EXAMPLE" ><TR ><TD ><DIV CLASS="example" ><A NAME="AEN228756" ></A ><P ><B >例 1. Usage example of <B CLASS="function" >trim()</B ></B ></P ><TABLE BORDER="0" BGCOLOR="#E0E0E0" CELLPADDING="5" ><TR ><TD ><code><font color="#000000"> <font color="#0000BB"><?php<br /><br />$text </font><font color="#007700">= </font><font color="#DD0000">"\t\tThese are a few words :) ... "</font><font color="#007700">;<br /></font><font color="#0000BB">$binary </font><font color="#007700">= </font><font color="#DD0000">"\x09Example string\x0A"</font><font color="#007700">;<br /></font><font color="#0000BB">$hello </font><font color="#007700">= </font><font color="#DD0000">"Hello World"</font><font color="#007700">;<br /></font><font color="#0000BB">var_dump</font><font color="#007700">(</font><font color="#0000BB">$text</font><font color="#007700">, </font><font color="#0000BB">$binary</font><font color="#007700">, </font><font color="#0000BB">$hello</font><font color="#007700">);<br /><br />print </font><font color="#DD0000">"\n"</font><font color="#007700">;<br /><br /></font><font color="#0000BB">$trimmed </font><font color="#007700">= </font><font color="#0000BB">trim</font><font color="#007700">(</font><font color="#0000BB">$text</font><font color="#007700">);<br /></font><font color="#0000BB">var_dump</font><font color="#007700">(</font><font color="#0000BB">$trimmed</font><font color="#007700">);<br /><br /></font><font color="#0000BB">$trimmed </font><font color="#007700">= </font><font color="#0000BB">trim</font><font color="#007700">(</font><font color="#0000BB">$text</font><font color="#007700">, </font><font color="#DD0000">" \t."</font><font color="#007700">);<br /></font><font color="#0000BB">var_dump</font><font color="#007700">(</font><font color="#0000BB">$trimmed</font><font color="#007700">);<br /><br /></font><font color="#0000BB">$trimmed </font><font color="#007700">= </font><font color="#0000BB">trim</font><font color="#007700">(</font><font color="#0000BB">$hello</font><font color="#007700">, </font><font color="#DD0000">"Hdle"</font><font color="#007700">);<br /></font><font color="#0000BB">var_dump</font><font color="#007700">(</font><font color="#0000BB">$trimmed</font><font color="#007700">);<br /><br /></font><font color="#FF8000">// trim the ASCII control characters at the beginning and end of $binary<br />// (from 0 to 31 inclusive)<br /></font><font color="#0000BB">$clean </font><font color="#007700">= </font><font color="#0000BB">trim</font><font color="#007700">(</font><font color="#0000BB">$binary</font><font color="#007700">, </font><font color="#DD0000">"\x00..\x1F"</font><font color="#007700">);<br /></font><font color="#0000BB">var_dump</font><font color="#007700">(</font><font color="#0000BB">$clean</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" >string(32) " These are a few words :) ... " string(16) " Example string " string(11) "Hello World" string(28) "These are a few words :) ..." string(24) "These are a few words :)" string(5) "o Wor" string(14) "Example string"</PRE ></TD ></TR ></TABLE ></DIV ></TD ></TR ></TABLE > </P ><P > <TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" CLASS="EXAMPLE" ><TR ><TD ><DIV CLASS="example" ><A NAME="AEN228763" ></A ><P ><B >例 2. Trimming array values with <B CLASS="function" >trim()</B ></B ></P ><TABLE BORDER="0" BGCOLOR="#E0E0E0" CELLPADDING="5" ><TR ><TD ><code><font color="#000000"> <font color="#0000BB"><?php<br /></font><font color="#007700">function </font><font color="#0000BB">trim_value</font><font color="#007700">(&</font><font color="#0000BB">$value</font><font color="#007700">) <br />{ <br /> </font><font color="#0000BB">$value </font><font color="#007700">= </font><font color="#0000BB">trim</font><font color="#007700">(</font><font color="#0000BB">$value</font><font color="#007700">); <br />}<br /><br /></font><font color="#0000BB">$fruit </font><font color="#007700">= array(</font><font color="#DD0000">'apple'</font><font color="#007700">,</font><font color="#DD0000">'banana '</font><font color="#007700">, </font><font color="#DD0000">' cranberry '</font><font color="#007700">);<br /></font><font color="#0000BB">var_dump</font><font color="#007700">(</font><font color="#0000BB">$fruit</font><font color="#007700">);<br /><br /></font><font color="#0000BB">array_walk</font><font color="#007700">(</font><font color="#0000BB">$fruit</font><font color="#007700">, </font><font color="#DD0000">'trim_value'</font><font color="#007700">);<br /></font><font color="#0000BB">var_dump</font><font color="#007700">(</font><font color="#0000BB">$fruit</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" >array(3) { [0]=> string(5) "apple" [1]=> string(7) "banana " [2]=> string(11) " cranberry " } array(3) { [0]=> string(5) "apple" [1]=> string(6) "banana" [2]=> string(9) "cranberry" }</PRE ></TD ></TR ></TABLE ></DIV ></TD ></TR ></TABLE > </P ></DIV ><DIV CLASS="refsect1" ><A NAME="AEN228769" ></A ><H2 >参见</H2 ><P > <P ></P ><TABLE BORDER="0" ><TBODY ><TR ><TD ><A HREF="function.ltrim.html" ><B CLASS="function" >ltrim()</B ></A ></TD ></TR ><TR ><TD ><A HREF="function.rtrim.html" ><B CLASS="function" >rtrim()</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.substr.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.ucfirst.html" ACCESSKEY="N" >下一页</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >substr</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" >ucfirst</TD ></TR ></TABLE ></DIV ></BODY ></HTML >