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9912944367
git-svn-id: https://svn.php.net/repository/phpdoc/zh/trunk@95633 c90b9560-bf6c-de11-be94-00142212c4b1
86 lines
2.3 KiB
XML
Executable File
86 lines
2.3 KiB
XML
Executable File
<?xml version="1.0" encoding="gb2312"?>
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<!-- $Revision: 1.1 $ -->
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<!-- $Author: dallas $ -->
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<!-- EN-Revision: 1.4 Maintainer: dallas Status: ready -->
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<refentry id="function.count">
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<refnamediv>
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<refname>count</refname>
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<refpurpose>统计变量中的单元数目</refpurpose>
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</refnamediv>
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<refsect1>
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<title>说明</title>
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<methodsynopsis>
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<type>int</type><methodname>count</methodname>
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<methodparam><type>mixed</type><parameter>var</parameter></methodparam>
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</methodsynopsis>
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<para>
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返回 <parameter>var</parameter> 中的单元数目，通常是一个
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<type>array</type>（任何其它类型都只有一个单元）。
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</para>
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<para>
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如果 <parameter>var</parameter> 不是数组类型，将返回
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<literal>1</literal>（例外：<literal>count(&null;)</literal> 的结果是 <literal>0</literal>）。
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</para>
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<warning>
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<para>
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<function>count</function> 对没有初始化的变量返回 0，但对于空的数组也会返回 0。用
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<function>isset</function> 来测试变量是否已经初始化。
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</para>
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</warning>
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<para>
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请参考手册中<link linkend="language.types.array">数组</link>一节中关于怎样在
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PHP 中实现和使用数组的详细解释。
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</para>
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<para>
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<example>
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<title><function>count</function> 例子</title>
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<programlisting role="php">
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<!-- TODO: examples about count(null), count(false), count(object).. -->
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<![CDATA[
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$a[0] = 1;
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$a[1] = 3;
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$a[2] = 5;
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$result = count ($a);
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// $result == 3
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$b[0] = 7;
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$b[5] = 9;
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$b[10] = 11;
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$result = count ($b);
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// $result == 3;
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]]>
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</programlisting>
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</example>
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</para>
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<note>
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<para>
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<function>sizeof</function> 函数是 <function>count</function> 的<link linkend="aliases">别名</link>。
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</para>
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</note>
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<para>
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参见 <function>is_array</function>，<function>isset</function> 和 <function>strlen</function>。
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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:"../../../../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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