<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <HTML ><HEAD ><TITLE >array_map</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="Array 数组函数" HREF="ref.array.html"><LINK REL="PREVIOUS" TITLE="array_keys" HREF="function.array-keys.html"><LINK REL="NEXT" TITLE="array_merge_recursive" HREF="function.array-merge-recursive.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.array-keys.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.array-merge-recursive.html" ACCESSKEY="N" >下一页</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="function.array-map" ></A >array_map</H1 ><DIV CLASS="refnamediv" ><A NAME="AEN11355" ></A ><P > (PHP 4 >= 4.0.6, PHP 5)</P >array_map -- 将回调函数作用到给定数组的单元上 </DIV ><DIV CLASS="refsect1" ><A NAME="AEN11358" ></A ><H2 >说明</H2 >array <B CLASS="methodname" >array_map</B > ( callback callback, array arr1 [, array ...] )<BR ></BR ><P > <B CLASS="function" >array_map()</B > 返回一个数组,该数组包含了 <CODE CLASS="parameter" >arr1</CODE > 中的所有单元经过 <CODE CLASS="parameter" >callback</CODE > 作用过之后的单元。<CODE CLASS="parameter" >callback</CODE > 接受的参数数目应该和传递给 <B CLASS="function" >array_map()</B > 函数的数组数目一致。 </P ><P > <TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" CLASS="EXAMPLE" ><TR ><TD ><DIV CLASS="example" ><A NAME="AEN11379" ></A ><P ><B >例 1. <B CLASS="function" >array_map()</B > 例子</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">cube</font><font color="#007700">(</font><font color="#0000BB">$n</font><font color="#007700">)<br />{<br /> return(</font><font color="#0000BB">$n </font><font color="#007700">* </font><font color="#0000BB">$n </font><font color="#007700">* </font><font color="#0000BB">$n</font><font color="#007700">);<br />}<br /><br /></font><font color="#0000BB">$a </font><font color="#007700">= array(</font><font color="#0000BB">1</font><font color="#007700">, </font><font color="#0000BB">2</font><font color="#007700">, </font><font color="#0000BB">3</font><font color="#007700">, </font><font color="#0000BB">4</font><font color="#007700">, </font><font color="#0000BB">5</font><font color="#007700">);<br /></font><font color="#0000BB">$b </font><font color="#007700">= </font><font color="#0000BB">array_map</font><font color="#007700">(</font><font color="#DD0000">"cube"</font><font color="#007700">, </font><font color="#0000BB">$a</font><font color="#007700">);<br /></font><font color="#0000BB">print_r</font><font color="#007700">(</font><font color="#0000BB">$b</font><font color="#007700">);<br /></font><font color="#0000BB">?></font> </font> </code></TD ></TR ></TABLE ><P > 这使得 <CODE CLASS="varname" >$b</CODE > 成为: </P ><TABLE BORDER="0" BGCOLOR="#E0E0E0" CELLPADDING="5" ><TR ><TD ><PRE CLASS="screen" >Array ( [0] => 1 [1] => 8 [2] => 27 [3] => 64 [4] => 125 )</PRE ></TD ></TR ></TABLE ></DIV ></TD ></TR ></TABLE > </P ><P > <TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" CLASS="EXAMPLE" ><TR ><TD ><DIV CLASS="example" ><A NAME="AEN11387" ></A ><P ><B >例 2. <B CLASS="function" >array_map()</B > - 使用更多的数组</B ></P ><TABLE BORDER="0" BGCOLOR="#E0E0E0" CELLPADDING="5" ><TR ><TD ><code><font color="#000000"> <font color="#0000BB"><?php<br /></font><font color="#007700">function </font><font color="#0000BB">show_Spanish</font><font color="#007700">(</font><font color="#0000BB">$n</font><font color="#007700">, </font><font color="#0000BB">$m</font><font color="#007700">)<br />{<br /> return(</font><font color="#DD0000">"The number $n is called $m in Spanish"</font><font color="#007700">);<br />}<br /><br />function </font><font color="#0000BB">map_Spanish</font><font color="#007700">(</font><font color="#0000BB">$n</font><font color="#007700">, </font><font color="#0000BB">$m</font><font color="#007700">)<br />{<br /> return(array(</font><font color="#0000BB">$n </font><font color="#007700">=> </font><font color="#0000BB">$m</font><font color="#007700">));<br />}<br /><br /></font><font color="#0000BB">$a </font><font color="#007700">= array(</font><font color="#0000BB">1</font><font color="#007700">, </font><font color="#0000BB">2</font><font color="#007700">, </font><font color="#0000BB">3</font><font color="#007700">, </font><font color="#0000BB">4</font><font color="#007700">, </font><font color="#0000BB">5</font><font color="#007700">);<br /></font><font color="#0000BB">$b </font><font color="#007700">= array(</font><font color="#DD0000">"uno"</font><font color="#007700">, </font><font color="#DD0000">"dos"</font><font color="#007700">, </font><font color="#DD0000">"tres"</font><font color="#007700">, </font><font color="#DD0000">"cuatro"</font><font color="#007700">, </font><font color="#DD0000">"cinco"</font><font color="#007700">);<br /><br /></font><font color="#0000BB">$c </font><font color="#007700">= </font><font color="#0000BB">array_map</font><font color="#007700">(</font><font color="#DD0000">"show_Spanish"</font><font color="#007700">, </font><font color="#0000BB">$a</font><font color="#007700">, </font><font color="#0000BB">$b</font><font color="#007700">);<br /></font><font color="#0000BB">print_r</font><font color="#007700">(</font><font color="#0000BB">$c</font><font color="#007700">);<br /><br /></font><font color="#0000BB">$d </font><font color="#007700">= </font><font color="#0000BB">array_map</font><font color="#007700">(</font><font color="#DD0000">"map_Spanish"</font><font color="#007700">, </font><font color="#0000BB">$a </font><font color="#007700">, </font><font color="#0000BB">$b</font><font color="#007700">);<br /></font><font color="#0000BB">print_r</font><font color="#007700">(</font><font color="#0000BB">$d</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" >// printout of $c Array ( [0] => The number 1 is called uno in Spanish [1] => The number 2 is called dos in Spanish [2] => The number 3 is called tres in Spanish [3] => The number 4 is called cuatro in Spanish [4] => The number 5 is called cinco in Spanish ) // printout of $d Array ( [0] => Array ( [1] => uno ) [1] => Array ( [2] => dos ) [2] => Array ( [3] => tres ) [3] => Array ( [4] => cuatro ) [4] => Array ( [5] => cinco ) )</PRE ></TD ></TR ></TABLE ></DIV ></TD ></TR ></TABLE > </P ><P > 通常使用了两个或更多数组时,它们的长度应该相同,因为回调函数是平行作用于相应的单元上的。如果数组的长度不同,则最短的一个将被用空的单元扩充。 </P ><P > 本函数一个有趣的用法是构造一个数组的数组,这可以很容易的通过用 <TT CLASS="constant" ><B >NULL</B ></TT > 作为回调函数名来实现。 </P ><P > <TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" CLASS="EXAMPLE" ><TR ><TD ><DIV CLASS="example" ><A NAME="AEN11397" ></A ><P ><B >例 3. 建立一个数组的数组</B ></P ><TABLE BORDER="0" BGCOLOR="#E0E0E0" CELLPADDING="5" ><TR ><TD ><code><font color="#000000"> <font color="#0000BB"><?php<br />$a </font><font color="#007700">= array(</font><font color="#0000BB">1</font><font color="#007700">, </font><font color="#0000BB">2</font><font color="#007700">, </font><font color="#0000BB">3</font><font color="#007700">, </font><font color="#0000BB">4</font><font color="#007700">, </font><font color="#0000BB">5</font><font color="#007700">);<br /></font><font color="#0000BB">$b </font><font color="#007700">= array(</font><font color="#DD0000">"one"</font><font color="#007700">, </font><font color="#DD0000">"two"</font><font color="#007700">, </font><font color="#DD0000">"three"</font><font color="#007700">, </font><font color="#DD0000">"four"</font><font color="#007700">, </font><font color="#DD0000">"five"</font><font color="#007700">);<br /></font><font color="#0000BB">$c </font><font color="#007700">= array(</font><font color="#DD0000">"uno"</font><font color="#007700">, </font><font color="#DD0000">"dos"</font><font color="#007700">, </font><font color="#DD0000">"tres"</font><font color="#007700">, </font><font color="#DD0000">"cuatro"</font><font color="#007700">, </font><font color="#DD0000">"cinco"</font><font color="#007700">);<br /><br /></font><font color="#0000BB">$d </font><font color="#007700">= </font><font color="#0000BB">array_map</font><font color="#007700">(</font><font color="#0000BB">null</font><font color="#007700">, </font><font color="#0000BB">$a</font><font color="#007700">, </font><font color="#0000BB">$b</font><font color="#007700">, </font><font color="#0000BB">$c</font><font color="#007700">);<br /></font><font color="#0000BB">print_r</font><font color="#007700">(</font><font color="#0000BB">$d</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" >Array ( [0] => Array ( [0] => 1 [1] => one [2] => uno ) [1] => Array ( [0] => 2 [1] => two [2] => dos ) [2] => Array ( [0] => 3 [1] => three [2] => tres ) [3] => Array ( [0] => 4 [1] => four [2] => cuatro ) [4] => Array ( [0] => 5 [1] => five [2] => cinco ) )</PRE ></TD ></TR ></TABLE ></DIV ></TD ></TR ></TABLE > </P ><P > 参见 <A HREF="function.array-filter.html" ><B CLASS="function" >array_filter()</B ></A >,<A HREF="function.array-reduce.html" ><B CLASS="function" >array_reduce()</B ></A >,<A HREF="function.array-walk.html" ><B CLASS="function" >array_walk()</B ></A > 和有关 <A HREF="language.pseudo-types.html#language.types.callback" >callback</A > 类型的信息。 </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.array-keys.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.array-merge-recursive.html" ACCESSKEY="N" >下一页</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >array_keys</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="ref.array.html" ACCESSKEY="U" >上一级</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >array_merge_recursive</TD ></TR ></TABLE ></DIV ></BODY ></HTML >