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WS Fix

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git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@165578 c90b9560-bf6c-de11-be94-00142212c4b1
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Curt Zirzow 2004-08-06 23:50:50 +00:00
parent f8ab0f13f0
commit d2b7dd3054
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123
language/oop5/decon.xml
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@ -1,92 +1,93 @@
<?xml version="1.0" encoding="iso-8859-1"?>
<!-- $Revision: 1.1 $ -->
<!-- $Revision: 1.2 $ -->
<sect1 id="language.oop5.decon">
<title>Constructors and Destructors</title>
<sect2 id="oop5-decon-constructor">
<title>Constructor</title>
<para>
PHP 5 allows developers to declare constructor methods for classes.
Classes which have a constructor method call this method on each
newly-created object, so it is suitable for any initialization that the
object may need before it is used.
</para>
<note>
<simpara>
Parent constructors are not called implicitly. In order to run
a parent constructor, a call to
<function>parent::__construct</function> is required.
</simpara>
</note>
<example>
<title>using new unified constructors</title>
<programlisting role="php">
<title>Constructor</title>
<para>
PHP 5 allows developers to declare constructor methods for classes.
Classes which have a constructor method call this method on each
newly-created object, so it is suitable for any initialization that the
object may need before it is used.
</para>
<note>
<simpara>
Parent constructors are not called implicitly. In order to run
a parent constructor, a call to
<function>parent::__construct</function> is required.
</simpara>
</note>
<example>
<title>using new unified constructors</title>
<programlisting role="php">
<![CDATA[
<?php
class BaseClass {
function __construct() {
print "In BaseClass constructor\n";
}
function __construct() {
print "In BaseClass constructor\n";
}
}
class SubClass extends BaseClass {
function __construct() {
parent::__construct();
print "In SubClass constructor\n";
}
function __construct() {
parent::__construct();
print "In SubClass constructor\n";
}
}
$obj = new BaseClass();
$obj = new SubClass();
?>
]]>
</programlisting>
</example>
<para>
For backwards compatibility, if PHP 5 cannot find a
<function>__construct</function> function for a given class, it will
search for the old-style constructor function, by the name of the class.
Effectively, it means that the only case that would have compatibility
issues is if the class had a method named
<function>__construct</function> which was used for different semantics.
</para>
</programlisting>
</example>
<para>
For backwards compatibility, if PHP 5 cannot find a
<function>__construct</function> function for a given class, it will
search for the old-style constructor function, by the name of the class.
Effectively, it means that the only case that would have compatibility
issues is if the class had a method named
<function>__construct</function> which was used for different semantics.
</para>
</sect2>
<sect2 id="oop5-decon-destructor">
<title>Destructor</title>
<para>
PHP 5 introduces a destructor concept similar to that of other
object-oriented languages, such as Java: When the last reference to an
object is destroyed the object's destructor, which is a class method
named <function>__destruct</function> that receives no parameters, is
called before the object is freed from memory.
</para>
<example>
<title>Destructor Example</title>
<programlisting role="php">
<title>Destructor</title>
<para>
PHP 5 introduces a destructor concept similar to that of other
object-oriented languages, such as Java: When the last reference to an
object is destroyed the object's destructor, which is a class method
named <function>__destruct</function> that receives no parameters, is
called before the object is freed from memory.
</para>
<example>
<title>Destructor Example</title>
<programlisting role="php">
<![CDATA[
<?php
class MyDestructableClass {
function __construct() {
print "In constructor\n";
$this->name = "MyDestructableClass";
}
function __construct() {
print "In constructor\n";
$this->name = "MyDestructableClass";
}
function __destruct() {
print "Destroying " . $this->name . "\n";
}
function __destruct() {
print "Destroying " . $this->name . "\n";
}
}
$obj = new MyDestructableClass();
?>
]]>
</programlisting>
</example>
<para>
Like constructors, parent destructors will not be called implicitly by
the engine. In order to run a parent destructor, one would have to
explicitly call <function>parent::__destruct</function> in the destructor
body.
</para>
</programlisting>
</example>
<para>
Like constructors, parent destructors will not be called implicitly by
the engine. In order to run a parent destructor, one would have to
explicitly call <function>parent::__destruct</function> in the destructor
body.
</para>
</sect2>
</sect1>