reference/math/functions/is-infinite.xml
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<?xml version="1.0" encoding="utf-8"?>
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<!-- $Revision$ -->
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<refentry xml:id='function.is-infinite' xmlns="http://docbook.org/ns/docbook">
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<refentry xml:id="function.is-infinite" xmlns="http://docbook.org/ns/docbook">
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<refnamediv>
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<refname>is_infinite</refname>
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<refpurpose>Finds whether a value is infinite</refpurpose>
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<refpurpose>Checks whether a float is infinite</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>bool</type><methodname>is_infinite</methodname>
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<methodparam><type>float</type><parameter>val</parameter></methodparam>
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</methodsynopsis>
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<methodsynopsis>
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<type>bool</type><methodname>is_infinite</methodname>
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<methodparam><type>float</type><parameter>num</parameter></methodparam>
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</methodsynopsis>
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<para>
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Returns &true; if <parameter>val</parameter> is infinite (positive or
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negative), like the result of <literal>log(0)</literal> or any value too
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big to fit into a float on this platform.
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Returns whether the given <parameter>num</parameter> is either <literal>INF</literal>
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or <literal>-INF</literal>.
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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>val</parameter></term>
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<term><parameter>num</parameter></term>
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<listitem>
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<para>
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The value to check
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The &float; to check
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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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&true; if <parameter>val</parameter> is infinite, else &false;.
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&true; if <parameter>num</parameter> is either <literal>INF</literal>
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or <literal>-INF</literal>, else &false;.
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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><function>is_infinite</function> example</title>
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<programlisting role="php">
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<![CDATA[
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<?php
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$inf = 1e308 * 2;
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var_dump($inf, is_infinite($inf));
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$negative_inf = -$inf;
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var_dump($negative_inf, is_infinite($negative_inf));
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?>
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]]>
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</programlisting>
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&example.outputs;
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<screen>
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<![CDATA[
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float(INF)
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bool(true)
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float(-INF)
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bool(true)
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]]>
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</screen>
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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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</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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