mirror of
https://github.com/sigmasternchen/php-doc-en
synced 2025-03-19 18:38:55 +00:00
1db0fccd50
git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@298259 c90b9560-bf6c-de11-be94-00142212c4b1
158 lines
4 KiB
XML
158 lines
4 KiB
XML
<?xml version="1.0" encoding="utf-8"?>
|
|
<!-- $Revision$ -->
|
|
<refentry xml:id="function.array-reduce" xmlns="http://docbook.org/ns/docbook">
|
|
<refnamediv>
|
|
<refname>array_reduce</refname>
|
|
<refpurpose>Iteratively reduce the array to a single value using a callback function</refpurpose>
|
|
</refnamediv>
|
|
<refsect1 role="description">
|
|
&reftitle.description;
|
|
<methodsynopsis>
|
|
<type>mixed</type><methodname>array_reduce</methodname>
|
|
<methodparam><type>array</type><parameter>input</parameter></methodparam>
|
|
<methodparam><type>callback</type><parameter>function</parameter></methodparam>
|
|
<methodparam choice="opt"><type>mixed</type><parameter>initial</parameter><initializer>&null;</initializer></methodparam>
|
|
</methodsynopsis>
|
|
<para>
|
|
<function>array_reduce</function> applies iteratively the
|
|
<parameter>function</parameter> function to the elements of the
|
|
array <parameter>input</parameter>, so as to reduce the array to
|
|
a single value.
|
|
</para>
|
|
</refsect1>
|
|
<refsect1 role="parameters">
|
|
&reftitle.parameters;
|
|
<para>
|
|
<variablelist>
|
|
<varlistentry>
|
|
<term><parameter>input</parameter></term>
|
|
<listitem>
|
|
<para>
|
|
The input array.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
<varlistentry>
|
|
<term><parameter>function</parameter></term>
|
|
<listitem>
|
|
<para>
|
|
The callback function.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
<varlistentry>
|
|
<term><parameter>initial</parameter></term>
|
|
<listitem>
|
|
<para>
|
|
If the optional <parameter>initial</parameter> is available, it will
|
|
be used at the beginning of the process, or as a final result in case
|
|
the array is empty.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
</para>
|
|
</refsect1>
|
|
<refsect1 role="returnvalues">
|
|
&reftitle.returnvalues;
|
|
<para>
|
|
Returns the resulting value.
|
|
</para>
|
|
<para>
|
|
If the array is empty and <parameter>initial</parameter> is not passed,
|
|
<function>array_reduce</function> returns &null;.
|
|
</para>
|
|
</refsect1>
|
|
<refsect1 role="changelog">
|
|
&reftitle.changelog;
|
|
<para>
|
|
<informaltable>
|
|
<tgroup cols="2">
|
|
<thead>
|
|
<row>
|
|
<entry>&Version;</entry>
|
|
<entry>&Description;</entry>
|
|
</row>
|
|
</thead>
|
|
<tbody>
|
|
<row>
|
|
<entry>5.3.0</entry>
|
|
<entry>
|
|
Changed <parameter>initial</parameter> to allow <type>mixed</type>, previously <type>integer</type>.
|
|
</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</informaltable>
|
|
</para>
|
|
</refsect1>
|
|
<refsect1 role="examples">
|
|
&reftitle.examples;
|
|
<para>
|
|
<example>
|
|
<title><function>array_reduce</function> example</title>
|
|
<programlisting role="php">
|
|
<![CDATA[
|
|
<?php
|
|
function rsum($v, $w)
|
|
{
|
|
$v += $w;
|
|
return $v;
|
|
}
|
|
|
|
function rmul($v, $w)
|
|
{
|
|
$v *= $w;
|
|
return $v;
|
|
}
|
|
|
|
$a = array(1, 2, 3, 4, 5);
|
|
$x = array();
|
|
$b = array_reduce($a, "rsum");
|
|
$c = array_reduce($a, "rmul", 10);
|
|
$d = array_reduce($x, "rsum", "No data to reduce");
|
|
?>
|
|
]]>
|
|
</programlisting>
|
|
<para>
|
|
This will result in <varname>$b</varname> containing
|
|
<literal>15</literal>, <varname>$c</varname> containing
|
|
<literal>1200</literal> (= 10*1*2*3*4*5), and <varname>$d</varname>
|
|
containing <literal>No data to reduce</literal>.
|
|
</para>
|
|
</example>
|
|
</para>
|
|
</refsect1>
|
|
<refsect1 role="seealso">
|
|
&reftitle.seealso;
|
|
<para>
|
|
<simplelist>
|
|
<member><function>array_filter</function></member>
|
|
<member><function>array_map</function></member>
|
|
<member><function>array_unique</function></member>
|
|
<member><function>array_count_values</function></member>
|
|
</simplelist>
|
|
</para>
|
|
</refsect1>
|
|
</refentry>
|
|
|
|
<!-- Keep this comment at the end of the file
|
|
Local variables:
|
|
mode: sgml
|
|
sgml-omittag:t
|
|
sgml-shorttag:t
|
|
sgml-minimize-attributes:nil
|
|
sgml-always-quote-attributes:t
|
|
sgml-indent-step:1
|
|
sgml-indent-data:t
|
|
indent-tabs-mode:nil
|
|
sgml-parent-document:nil
|
|
sgml-default-dtd-file:"~/.phpdoc/manual.ced"
|
|
sgml-exposed-tags:nil
|
|
sgml-local-catalogs:nil
|
|
sgml-local-ecat-files:nil
|
|
End:
|
|
vim600: syn=xml fen fdm=syntax fdl=2 si
|
|
vim: et tw=78 syn=sgml
|
|
vi: ts=1 sw=1
|
|
-->
|