mirror of
https://github.com/sigmasternchen/php-doc-en
synced 2025-03-15 08:28:54 +00:00
New examples for classes (#750)
Co-authored-by: Anna Filina <afilina@gmail.com>
This commit is contained in:
parent
43ac336818
commit
6f11457f11
1 changed files with 86 additions and 73 deletions
|
@ -6,62 +6,66 @@
|
|||
<para>
|
||||
In this example, we first define a base class and an extension
|
||||
of the class. The base class describes a general vegetable,
|
||||
whether it is edible or not and what is its color. The subclass
|
||||
whether it is edible, and what is its color. The subclass
|
||||
<varname>Spinach</varname> adds a method to cook it and another to
|
||||
find out if it is cooked.
|
||||
</para>
|
||||
<para>
|
||||
<example>
|
||||
<title>classes.inc</title>
|
||||
<title>Class Definitions</title>
|
||||
<para><varname>Vegetable</varname></para>
|
||||
<programlisting role="php">
|
||||
<![CDATA[
|
||||
<?php
|
||||
|
||||
// base class with member properties and methods
|
||||
class Vegetable {
|
||||
public $edible;
|
||||
|
||||
var $edible;
|
||||
var $color;
|
||||
public $color;
|
||||
|
||||
function __construct($edible, $color="green")
|
||||
{
|
||||
$this->edible = $edible;
|
||||
$this->color = $color;
|
||||
}
|
||||
public function __construct($edible, $color = "green")
|
||||
{
|
||||
$this->edible = $edible;
|
||||
$this->color = $color;
|
||||
}
|
||||
|
||||
function is_edible()
|
||||
{
|
||||
return $this->edible;
|
||||
}
|
||||
public function isEdible()
|
||||
{
|
||||
return $this->edible;
|
||||
}
|
||||
|
||||
function what_color()
|
||||
{
|
||||
return $this->color;
|
||||
}
|
||||
public function getColor()
|
||||
{
|
||||
return $this->color;
|
||||
}
|
||||
}
|
||||
|
||||
} // end of class Vegetable
|
||||
?>
|
||||
]]>
|
||||
</programlisting>
|
||||
<para><varname>Spinach</varname></para>
|
||||
<programlisting role="php">
|
||||
<![CDATA[
|
||||
<?php
|
||||
|
||||
// extends the base class
|
||||
class Spinach extends Vegetable {
|
||||
public $cooked = false;
|
||||
|
||||
var $cooked = false;
|
||||
public function __construct()
|
||||
{
|
||||
parent::__construct(true, "green");
|
||||
}
|
||||
|
||||
function __construct()
|
||||
{
|
||||
parent::__construct(true, "green");
|
||||
}
|
||||
public function cook()
|
||||
{
|
||||
$this->cooked = true;
|
||||
}
|
||||
|
||||
function cook_it()
|
||||
{
|
||||
$this->cooked = true;
|
||||
}
|
||||
|
||||
function is_cooked()
|
||||
{
|
||||
return $this->cooked;
|
||||
}
|
||||
|
||||
} // end of class Spinach
|
||||
public function isCooked()
|
||||
{
|
||||
return $this->cooked;
|
||||
}
|
||||
}
|
||||
|
||||
?>
|
||||
]]>
|
||||
|
@ -79,40 +83,37 @@ class Spinach extends Vegetable {
|
|||
<title>test_script.php</title>
|
||||
<programlisting role="php">
|
||||
<![CDATA[
|
||||
<pre>
|
||||
<?php
|
||||
|
||||
include "classes.inc";
|
||||
// register autoloader to load classes
|
||||
spl_autoload_register();
|
||||
|
||||
// utility functions
|
||||
|
||||
function print_vars($obj)
|
||||
function printProperties($obj)
|
||||
{
|
||||
foreach (get_object_vars($obj) as $prop => $val) {
|
||||
echo "\t$prop = $val\n";
|
||||
}
|
||||
foreach (get_object_vars($obj) as $prop => $val) {
|
||||
echo "\t$prop = $val\n";
|
||||
}
|
||||
}
|
||||
|
||||
function print_methods($obj)
|
||||
function printMethods($obj)
|
||||
{
|
||||
$arr = get_class_methods(get_class($obj));
|
||||
foreach ($arr as $method) {
|
||||
echo "\tfunction $method()\n";
|
||||
}
|
||||
$arr = get_class_methods(get_class($obj));
|
||||
foreach ($arr as $method) {
|
||||
echo "\tfunction $method()\n";
|
||||
}
|
||||
}
|
||||
|
||||
function class_parentage($obj, $class)
|
||||
function objectBelongsTo($obj, $class)
|
||||
{
|
||||
if (is_subclass_of($GLOBALS[$obj], $class)) {
|
||||
echo "Object $obj belongs to class " . get_class($GLOBALS[$obj]);
|
||||
echo ", a subclass of $class\n";
|
||||
} else {
|
||||
echo "Object $obj does not belong to a subclass of $class\n";
|
||||
}
|
||||
if (is_subclass_of($obj, $class)) {
|
||||
echo "Object belongs to class " . get_class($obj);
|
||||
echo ", a subclass of $class\n";
|
||||
} else {
|
||||
echo "Object does not belong to a subclass of $class\n";
|
||||
}
|
||||
}
|
||||
|
||||
// instantiate 2 objects
|
||||
|
||||
$veggie = new Vegetable(true, "blue");
|
||||
$leafy = new Spinach();
|
||||
|
||||
|
@ -123,34 +124,47 @@ echo ", PARENT " . get_parent_class($leafy) . "\n";
|
|||
|
||||
// show veggie properties
|
||||
echo "\nveggie: Properties\n";
|
||||
print_vars($veggie);
|
||||
printProperties($veggie);
|
||||
|
||||
// and leafy methods
|
||||
echo "\nleafy: Methods\n";
|
||||
print_methods($leafy);
|
||||
printMethods($leafy);
|
||||
|
||||
echo "\nParentage:\n";
|
||||
class_parentage("leafy", "Spinach");
|
||||
class_parentage("leafy", "Vegetable");
|
||||
objectBelongsTo($leafy, Spinach::class);
|
||||
objectBelongsTo($leafy, Vegetable::class);
|
||||
|
||||
?>
|
||||
</pre>
|
||||
]]>
|
||||
</programlisting>
|
||||
&examples.outputs;
|
||||
<screen>
|
||||
<![CDATA[
|
||||
veggie: CLASS Vegetable
|
||||
leafy: CLASS Spinach, PARENT Vegetable
|
||||
|
||||
veggie: Properties
|
||||
edible = 1
|
||||
color = blue
|
||||
|
||||
leafy: Methods
|
||||
function __construct()
|
||||
function cook()
|
||||
function isCooked()
|
||||
function isEdible()
|
||||
function getColor()
|
||||
|
||||
Parentage:
|
||||
Object does not belong to a subclass of Spinach
|
||||
Object belongs to class Spinach, a subclass of Vegetable
|
||||
]]>
|
||||
</screen>
|
||||
<para>
|
||||
One important thing to note in the example above is that
|
||||
the object <varname>$leafy</varname> is an instance of the class
|
||||
<classname>Spinach</classname> which is a subclass of
|
||||
<classname>Vegetable</classname>,
|
||||
therefore the last part of the script above will output:
|
||||
<classname>Vegetable</classname>.
|
||||
</para>
|
||||
<screen>
|
||||
<![CDATA[
|
||||
[...]
|
||||
Parentage:
|
||||
Object leafy does not belong to a subclass of Spinach
|
||||
Object leafy belongs to class spinach, a subclass of Vegetable
|
||||
]]>
|
||||
</screen>
|
||||
</example>
|
||||
</para>
|
||||
</appendix>
|
||||
|
@ -175,4 +189,3 @@ vim600: syn=xml fen fdm=syntax fdl=2 si
|
|||
vim: et tw=78 syn=sgml
|
||||
vi: ts=1 sw=1
|
||||
-->
|
||||
|
||||
|
|
Loading…
Reference in a new issue