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https://github.com/sigmasternchen/php-doc-en
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c030e2adf7
- All id attributes are now xml:id - Add docbook namespace to all root elements - Replace <ulink /> with <link xlink:href /> - Minor markup fixes here and there git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@238160 c90b9560-bf6c-de11-be94-00142212c4b1
143 lines
3.6 KiB
XML
143 lines
3.6 KiB
XML
<?xml version="1.0" encoding="iso-8859-1"?>
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<!-- $Revision: 1.13 $ -->
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<refentry xml:id="function.pow" xmlns="http://docbook.org/ns/docbook">
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<refnamediv>
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<refname>pow</refname>
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<refpurpose>Exponential expression</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>number</type><methodname>pow</methodname>
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<methodparam><type>number</type><parameter>base</parameter></methodparam>
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<methodparam><type>number</type><parameter>exp</parameter></methodparam>
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</methodsynopsis>
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<para>
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Returns <parameter>base</parameter> raised to the power of
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<parameter>exp</parameter>.
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</para>
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<warning>
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<para>
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In PHP 4.0.6 and earlier <function>pow</function> always returned
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a <type>float</type>, and did not issue warnings.
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</para>
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</warning>
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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>base</parameter></term>
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<listitem>
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<para>
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The base to use
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><parameter>exp</parameter></term>
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<listitem>
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<para>
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The exponent
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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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<parameter>base</parameter> raised to the power of <parameter>exp</parameter>.
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If the result can be represented as integer it will be returned as type
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<type>integer</type>, else it will be returned as type <type>float</type>.
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If the power cannot be computed &false; will be returned instead.
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</para>
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</refsect1>
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<refsect1 role="changelog">
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&reftitle.changelog;
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<para>
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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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<row>
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<entry>Since 4.0.6</entry>
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<entry>
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The function will now return <type>integer</type> results if possible,
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before this it always returned a <type>float</type> result. For older
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versions, you may receive a bogus result for complex numbers.
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</entry>
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</row>
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<row>
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<entry>Since 4.2.0</entry>
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<entry>
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PHP stops to emit a warning if the value can't be computed,
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it will now silently return &false; only.
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</entry>
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</row>
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</tbody>
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</tgroup>
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</informaltable>
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</para>
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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>Some examples of <function>pow</function></title>
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<programlisting role="php">
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<![CDATA[
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<?php
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var_dump(pow(2, 8)); // int(256)
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echo pow(-1, 20); // 1
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echo pow(0, 0); // 1
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echo pow(-1, 5.5); // PHP >4.0.6 NAN
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echo pow(-1, 5.5); // PHP <=4.0.6 1.#IND
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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="seealso">
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&reftitle.seealso;
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<para>
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<simplelist>
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<member><function>exp</function></member>
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<member><function>sqrt</function></member>
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<member><function>bcpow</function></member>
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<member><function>gmp_pow</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:"../../../../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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