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132 lines
3.4 KiB
XML
Executable File
132 lines
3.4 KiB
XML
Executable File
<?xml version="1.0" encoding="utf-8"?>
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<!-- EN-Revision: 0a192fcd9cc43c0007de795063b4494974058992 Maintainer: dallas Status: ready -->
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<refentry xml:id="function.reset" xmlns="http://docbook.org/ns/docbook">
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<refnamediv>
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<refname>reset</refname>
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<refpurpose>将数组的内部指针指向第一个单元</refpurpose>
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</refnamediv>
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<refsect1 role="description">
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&reftitle.description;
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<methodsynopsis>
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<type>mixed</type><methodname>reset</methodname>
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<methodparam><type class="union"><type>array</type><type>object</type></type><parameter role="reference">array</parameter></methodparam>
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</methodsynopsis>
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<para>
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<function>reset</function> 将 <parameter>array</parameter>
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的内部指针倒回到第一个单元并返回第一个数组单元的值。
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</para>
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</refsect1>
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<refsect1 role="parameters">
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&reftitle.parameters;
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<para>
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<variablelist>
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<varlistentry>
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<term><parameter>array</parameter></term>
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<listitem>
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<para>
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输入的数组。
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</para>
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</listitem>
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</varlistentry>
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</variablelist>
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</para>
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</refsect1>
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<refsect1 role="returnvalues">
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&reftitle.returnvalues;
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<para>
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返回数组第一个单元的值，如果数组为空则返回 &false;。
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</para>
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&return.falseproblem;
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</refsect1>
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<refsect1 role="changelog">
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&reftitle.changelog;
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<informaltable>
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<tgroup cols="2">
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<thead>
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<row>
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<entry>&Version;</entry>
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<entry>&Description;</entry>
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</row>
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</thead>
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<tbody>
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&standard.changelog.calling-on-objects;
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</tbody>
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</tgroup>
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</informaltable>
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</refsect1>
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<refsect1 role="examples">
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&reftitle.examples;
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<para>
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<example>
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<title><function>reset</function> 例子</title>
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<programlisting role="php">
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<![CDATA[
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<?php
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$array = array('step one', 'step two', 'step three', 'step four');
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// 默认情况下，指针指向第一个元素
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echo current($array) . "<br />\n"; // "step one"
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// 跳过两步
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next($array);
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next($array);
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echo current($array) . "<br />\n"; // "step three"
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// 重置指针，重新指向第一个元素
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reset($array);
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echo current($array) . "<br />\n"; // "step one"
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?>
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]]>
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</programlisting>
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</example>
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</para>
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</refsect1>
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<refsect1 role="notes">
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&reftitle.notes;
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<note>
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<simpara>
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返回的值无法区分是空数组，还是第一个元素是 <type>bool</type> &false;。
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要正确检测数组第一个元素包含 &false; 的情况，首先要检测数组 <function>count</function>，
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或在调用 <function>reset</function> 后检测 <function>key</function> 不为 &null;。
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</simpara>
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</note>
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</refsect1>
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<refsect1 role="seealso">
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&reftitle.seealso;
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<para>
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<simplelist>
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<member><function>current</function></member>
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<member><function>each</function></member>
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<member><function>end</function></member>
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<member><function>next</function></member>
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<member><function>prev</function></member>
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<member><function>array_key_first</function></member>
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</simplelist>
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</para>
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</refsect1>
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</refentry>
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<!-- Keep this comment at the end of the file
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Local variables:
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mode: sgml
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sgml-omittag:t
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sgml-shorttag:t
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sgml-minimize-attributes:nil
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sgml-always-quote-attributes:t
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sgml-indent-step:1
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sgml-indent-data:t
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indent-tabs-mode:nil
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sgml-parent-document:nil
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sgml-default-dtd-file:"~/.phpdoc/manual.ced"
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sgml-exposed-tags:nil
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sgml-local-catalogs:nil
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sgml-local-ecat-files:nil
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End:
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vim600: syn=xml fen fdm=syntax fdl=2 si
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vim: et tw=78 syn=sgml
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vi: ts=1 sw=1
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-->
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