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https://github.com/sigmasternchen/php-doc-en
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a6a4d6ad6e
Similar to PR 938 for the PHP 8.0 `mixed` reserved word, this commit adds the new reserved word `never` to the list of "Other reserved words" and adds a mention of this to the Backward Incompatible Changes page in the migration guide. Co-authored-by: jrfnl <jrfnl@users.noreply.github.com> Closes GH-1434.
610 lines
16 KiB
XML
610 lines
16 KiB
XML
<?xml version="1.0" encoding="utf-8"?>
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<!-- $Revision$ -->
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<appendix xml:id="reserved" xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink">
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<title>List of Reserved Words</title>
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<para>
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The following is a listing of predefined identifiers in PHP. None
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of the identifiers listed here should be used as identifiers in any of
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your scripts unless explicitly noted otherwise. These lists include keywords and predefined variables,
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constant, and class names. These lists are neither exhaustive nor
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complete.
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</para>
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<sect1 xml:id="reserved.keywords">
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<title>List of Keywords</title>
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<simpara>
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These words have special meaning in PHP. Some of them represent things
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which look like functions, some look like constants, and so on - but
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they're not, really: they are language constructs.
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The following words cannot be used as constants, class names, function or method names.
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They are, however, allowed as property, constant, and
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method names of classes, interfaces and traits, except that
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<literal>class</literal> may not be used as constant name.
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</simpara>
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<table>
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<title>PHP Keywords</title>
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<tgroup cols="5">
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<tbody>
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<row>
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<entry>
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<function>__halt_compiler</function>
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</entry>
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<entry>
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<link linkend="language.oop5.abstract">abstract</link>
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</entry>
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<entry>
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<link linkend="language.operators.logical">and</link>
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</entry>
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<entry>
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<function>array</function>
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</entry>
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<entry>
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<link linkend="control-structures.foreach">as</link>
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</entry>
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</row>
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<row>
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<entry>
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<link linkend="control-structures.break">break</link>
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</entry>
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<entry>
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<link linkend="language.types.callable">callable</link>
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</entry>
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<entry>
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<link linkend="control-structures.switch">case</link>
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</entry>
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<entry>
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<link linkend="language.exceptions">catch</link>
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</entry>
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<entry>
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<link linkend="language.oop5.basic.class">class</link>
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</entry>
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</row>
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<row>
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<entry>
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<link linkend="language.oop5.cloning">clone</link>
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</entry>
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<entry>
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<link linkend="language.oop5.constants">const</link>
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</entry>
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<entry>
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<link linkend="control-structures.continue">continue</link>
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</entry>
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<entry>
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<link linkend="control-structures.declare">declare</link>
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</entry>
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<entry>
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<link linkend="control-structures.switch">default</link>
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</entry>
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</row>
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<row>
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<entry>
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<function>die</function>
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</entry>
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<entry>
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<link linkend="control-structures.do.while">do</link>
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</entry>
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<entry>
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<function>echo</function>
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</entry>
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<entry>
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<link linkend="control-structures.else">else</link>
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</entry>
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<entry>
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<link linkend="control-structures.elseif">elseif</link>
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</entry>
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</row>
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<row>
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<entry>
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<function>empty</function>
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</entry>
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<entry>
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<link linkend="control-structures.declare">enddeclare</link>
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</entry>
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<entry>
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<link linkend="control-structures.alternative-syntax">endfor</link>
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</entry>
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<entry>
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<link linkend="control-structures.alternative-syntax">endforeach</link>
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</entry>
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<entry>
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<link linkend="control-structures.alternative-syntax">endif</link>
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</entry>
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</row>
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<row>
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<entry>
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<link linkend="control-structures.alternative-syntax">endswitch</link>
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</entry>
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<entry>
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<link linkend="control-structures.alternative-syntax">endwhile</link>
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</entry>
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<entry>
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<function>eval</function>
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</entry>
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<entry>
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<function>exit</function>
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</entry>
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<entry>
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<link linkend="language.oop5.basic.extends">extends</link>
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</entry>
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</row>
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<row>
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<entry>
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<link linkend="language.oop5.final">final</link>
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</entry>
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<entry>
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<link linkend="language.exceptions">finally</link>
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</entry>
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<entry>
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<link linkend="functions.arrow">fn</link> (as of PHP 7.4)
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</entry>
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<entry>
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<link linkend="control-structures.for">for</link>
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</entry>
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<entry>
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&foreach;
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</entry>
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</row>
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<row>
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<entry>
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<link linkend="functions.user-defined">function</link>
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</entry>
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<entry>
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<link linkend="language.variables.scope">global</link>
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</entry>
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<entry>
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<link linkend="control-structures.goto">goto</link>
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</entry>
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<entry>
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<link linkend="control-structures.if">if</link>
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</entry>
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<entry>
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<link linkend="language.oop5.interfaces">implements</link>
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</entry>
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</row>
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<row>
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<entry>
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<function>include</function>
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</entry>
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<entry>
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<function>include_once</function>
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</entry>
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<entry>
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<link linkend="language.operators.type">instanceof</link>
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</entry>
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<entry>
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<link linkend="language.oop5.traits.conflict">insteadof</link>
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</entry>
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<entry>
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<link linkend="language.oop5.interfaces">interface</link>
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</entry>
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</row>
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<row>
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<entry>
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<function>isset</function>
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</entry>
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<entry>
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<function>list</function>
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</entry>
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<entry>
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<link linkend="control-structures.match">match</link> (as of PHP 8.0)
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</entry>
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<entry>
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<link linkend="language.namespaces">namespace</link>
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</entry>
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<entry>
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<link linkend="language.oop5.basic.new">new</link>
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</entry>
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</row>
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<row>
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<entry>
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<link linkend="language.operators.logical">or</link>
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</entry>
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<entry>
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<function>print</function>
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</entry>
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<entry>
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<link linkend="language.oop5.visibility">private</link>
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</entry>
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<entry>
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<link linkend="language.oop5.visibility">protected</link>
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</entry>
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<entry>
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<link linkend="language.oop5.visibility">public</link>
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</entry>
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</row>
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<row>
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<entry>
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<link linkend="language.oop5.properties.readonly-properties">readonly</link> (as of PHP 8.1.0) *
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</entry>
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<entry>
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<function>require</function>
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</entry>
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<entry>
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<function>require_once</function>
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</entry>
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<entry>
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<function>return</function>
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</entry>
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<entry>
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<link linkend="language.variables.scope">static</link>
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</entry>
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</row>
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<row>
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<entry>
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<link linkend="control-structures.switch">switch</link>
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</entry>
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<entry>
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<link linkend="language.exceptions">throw</link>
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</entry>
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<entry>
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<link linkend="language.oop5.traits">trait</link>
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</entry>
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<entry>
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<link linkend="language.exceptions">try</link>
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</entry>
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<entry>
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<function>unset</function>
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</entry>
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</row>
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<row>
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<entry>
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<link linkend="language.namespaces">use</link>
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</entry>
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<entry>
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<link linkend="language.oop5.properties">var</link>
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</entry>
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<entry>
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<link linkend="control-structures.while">while</link>
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</entry>
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<entry>
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<link linkend="language.operators.logical">xor</link>
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</entry>
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<entry>
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<link linkend="language.generators">yield</link>
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</entry>
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</row>
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<row>
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<entry>
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<link linkend="control-structures.yield.from">yield from</link>
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</entry>
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<entry></entry>
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<entry></entry>
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<entry></entry>
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<entry></entry>
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</row>
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</tbody>
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</tgroup>
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</table>
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<simpara>
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* <literal>readonly</literal> may be used as function name.
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</simpara>
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<table>
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<title>Compile-time constants</title>
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<tgroup cols="5">
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<tbody>
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<row>
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<entry>
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<link linkend="language.constants.predefined">__CLASS__</link>
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</entry>
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<entry>
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<link linkend="language.constants.predefined">__DIR__</link>
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</entry>
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<entry>
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<link linkend="language.constants.predefined">__FILE__</link>
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</entry>
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<entry>
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<link linkend="language.constants.predefined">__FUNCTION__</link>
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</entry>
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<entry>
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<link linkend="language.constants.predefined">__LINE__</link>
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</entry>
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<entry>
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<link linkend="language.constants.predefined">__METHOD__</link>
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</entry>
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</row>
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<row>
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<entry>
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<link linkend="language.namespaces.nsconstants">__NAMESPACE__</link>
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</entry>
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<entry>
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<link linkend="language.constants.predefined">__TRAIT__</link>
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</entry>
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<entry>
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</entry>
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<entry>
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</entry>
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<entry>
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</entry>
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<entry>
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</entry>
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</row>
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</tbody>
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</tgroup>
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</table>
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</sect1>
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<sect1 xml:id="reserved.classes">
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<title>Predefined Classes</title>
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<para>
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This section lists standard predefined classes. Miscellaneous extensions
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define other classes which are described in their reference.
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</para>
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<sect2 xml:id="reserved.classes.standard">
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<title>Standard Defined Classes</title>
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<simpara>
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These classes are defined in the standard set of functions included
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in the PHP build.
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</simpara>
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<variablelist>
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<varlistentry>
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<term><classname>Directory</classname></term>
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<listitem>
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<simpara>
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Created by <function>dir</function>.
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</simpara>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><classname>stdClass</classname></term>
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<listitem>
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<simpara>
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Created by <link linkend="language.types.object.casting">typecasting
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to object</link>.
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</simpara>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><classname>__PHP_Incomplete_Class</classname></term>
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<listitem>
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<simpara>
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Possibly created by <function>unserialize</function>.
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</simpara>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><classname>Exception</classname></term>
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<listitem>
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<simpara>
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</simpara>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><classname>ErrorException</classname></term>
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<listitem>
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<simpara>
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</simpara>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><classname>php_user_filter</classname></term>
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<listitem>
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<simpara>
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</simpara>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><classname>Closure</classname></term>
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<listitem>
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<simpara>
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The predefined final class <classname>Closure</classname>
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is used for representing <link
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linkend="functions.anonymous">anonymous functions</link>.
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</simpara>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><classname>Generator</classname></term>
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<listitem>
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<simpara>
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The predefined final class <classname>Generator</classname>
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is used for representing <link
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linkend="language.generators">generators</link>.
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</simpara>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><classname>ArithmeticError</classname></term>
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<listitem>
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<simpara>
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</simpara>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><classname>AssertionError</classname></term>
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<listitem>
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<simpara>
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</simpara>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><classname>DivisionByZeroError</classname></term>
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<listitem>
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<simpara>
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</simpara>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><classname>Error</classname></term>
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<listitem>
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<simpara>
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</simpara>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><classname>Throwable</classname></term>
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<listitem>
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<simpara>
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</simpara>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><classname>ParseError</classname></term>
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<listitem>
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<simpara>
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</simpara>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><classname>TypeError</classname></term>
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<listitem>
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<simpara>
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</simpara>
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</listitem>
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</varlistentry>
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</variablelist>
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</sect2>
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<sect2 xml:id="reserved.classes.special">
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<title>Special classes</title>
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<simpara>
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Following identifiers may not be used as a class name as they have
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special purpose.
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</simpara>
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<variablelist>
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<varlistentry>
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<term><classname>self</classname></term>
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<listitem>
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<simpara>
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<link linkend="language.oop5.paamayim-nekudotayim">Current
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class</link>.
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</simpara>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><classname>static</classname></term>
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<listitem>
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<simpara>
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<link linkend="language.oop5.late-static-bindings">Current class in
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runtime</link>.
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</simpara>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><classname>parent</classname></term>
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<listitem>
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<simpara>
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<link linkend="language.oop5.paamayim-nekudotayim">Parent
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class</link>.
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</simpara>
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</listitem>
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</varlistentry>
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</variablelist>
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</sect2>
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</sect1>
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&appendices.reserved.constants;
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<sect1 xml:id="reserved.other-reserved-words">
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<title>List of other reserved words</title>
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<simpara>
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The following words cannot be used to name a class, interface or trait, and
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they are also prohibited from being used in namespaces.
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</simpara>
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<para>
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<table>
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<title>Reserved words</title>
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<tgroup cols="5">
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<tbody>
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<row>
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<entry>
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int
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</entry>
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<entry>
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float
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</entry>
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<entry>
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bool
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</entry>
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<entry>
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string
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</entry>
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</row>
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<row>
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<entry>
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true
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</entry>
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<entry>
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false
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</entry>
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<entry>
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null
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</entry>
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<entry>
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void (as of PHP 7.1)
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</entry>
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</row>
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<row>
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<entry>
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iterable (as of PHP 7.1)
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</entry>
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<entry>
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object (as of PHP 7.2)
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</entry>
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<entry>
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mixed (as of PHP 8.0)
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</entry>
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<entry>
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never (as of PHP 8.1)
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</entry>
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</row>
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</tbody>
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</tgroup>
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</table>
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</para>
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<para>
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The following list of words have had soft reservations placed on them.
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Whilst they may still be used as class, interface, and trait names (as well
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as in namespaces), usage of them is highly discouraged since they may be
|
|
used in future versions of PHP.
|
|
</para>
|
|
<para>
|
|
<table>
|
|
<title>Soft reserved words</title>
|
|
<tgroup cols="5">
|
|
<tbody>
|
|
<row>
|
|
<entry>
|
|
resource
|
|
</entry>
|
|
<entry>
|
|
numeric
|
|
</entry>
|
|
<entry>
|
|
</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
</para>
|
|
</sect1>
|
|
</appendix>
|
|
|
|
<!-- 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
|
|
-->
|