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<?xml version="1.0" encoding="iso-8859-1"?>
<!-- $Revision: 1.5 $ -->
<sect1 id="language.oop5.final">
<title>Final Keyword</title>
<para>
PHP 5 introduces the final keyword, which prevents child classes from
overriding a method by prefixing the definition with final. If the class
itself is being defined final then it cannot be extended.
</para>
<example>
<title>Final methods example</title>
<programlisting role="php">
<![CDATA[
<?php
class BaseClass {
public function test() {
echo "BaseClass::test() called\n";
}
final public function moreTesting() {
echo "BaseClass::moreTesting() called\n";
}
}
class ChildClass extends BaseClass {
public function moreTesting() {
echo "ChildClass::moreTesting() called\n";
}
}
// Results in Fatal error: Cannot override final method BaseClass::moreTesting()
?>
]]>
</programlisting>
</example>
<example>
<title>Final class example</title>
<programlisting role="php">
<![CDATA[
<?php
final class BaseClass {
public function test() {
echo "BaseClass::test() called\n";
}
// Here it doesn't matter if you specify the function as final or not
final public function moreTesting() {
echo "BaseClass::moreTesting() called\n";
}
}
class ChildClass extends BaseClass {
}
// Results in Fatal error: Class ChildClass may not inherit from final class (BaseClass)
?>
]]>
</programlisting>
</example>
</sect1>
<!-- 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:"../../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
-->
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