language/oop5/visibility.xml
f5e5b54129045a7d02c5285a88cea0abff8ffb6f
f5e5b54129045a7d02c5285a88cea0abff8ffb6f
...
...
@@ -3,12 +3,12 @@
3
3
<sect1 xml:id="language.oop5.visibility" xmlns="http://docbook.org/ns/docbook">
4
4
<title>Visibility</title>
5
5
<para>
6
-
The visibility of a property or method can be defined by prefixing
7
-
the declaration with the keywords <emphasis>public</emphasis>,
8
-
<emphasis>protected</emphasis> or
9
-
<emphasis>private</emphasis>. Class members declared public can be
6
+
The visibility of a property, a method or (as of PHP 7.1.0) a constant can be defined by prefixing
7
+
the declaration with the keywords <literal>public</literal>,
8
+
<literal>protected</literal> or
9
+
<literal>private</literal>. Class members declared public can be
10
10
accessed everywhere. Members declared protected can be accessed
11
-
only within the class itself and by inherited and parent
11
+
only within the class itself and by inheriting and parent
12
12
classes. Members declared as private may only be accessed by the
13
13
class that defines the member.
14
14
</para>
...
...
@@ -16,9 +16,9 @@
16
16
<sect2 xml:id="language.oop5.visibility-members">
17
17
<title>Property Visibility</title>
18
18
<para>
19
-
Class properties must be defined as public, private, or
20
-
protected. If declared using <emphasis>var</emphasis>,
21
-
the property will be defined as public.
19
+
Class properties may be defined as public, private, or
20
+
protected. Properties declared without any explicit visibility
21
+
keyword are defined as public.
22
22
</para>
23
23
<para>
24
24
<example>
...
...
@@ -55,7 +55,8 @@ $obj->printHello(); // Shows Public, Protected and Private
55
55
*/
56
56
class MyClass2 extends MyClass
57
57
{
58
-
// We can redeclare the public and protected method, but not private
58
+
// We can redeclare the public and protected properties, but not private
59
+
public $public = 'Public2';
59
60
protected $protected = 'Protected2';
60
61
61
62
function printHello()
...
...
@@ -70,21 +71,13 @@ $obj2 = new MyClass2();
70
71
echo $obj2->public; // Works
71
72
echo $obj2->protected; // Fatal Error
72
73
echo $obj2->private; // Undefined
73
-
$obj2->printHello(); // Shows Public, Protected2, Undefined
74
+
$obj2->printHello(); // Shows Public2, Protected2, Undefined
74
75
75
76
?>
76
77
]]>
77
78
</programlisting>
78
79
</example>
79
80
</para>
80
-
<note>
81
-
<simpara>
82
-
The PHP 4 method of declaring a variable with the
83
-
<emphasis>var</emphasis> keyword is still supported for compatibility
84
-
reasons (as a synonym for the public keyword). In PHP 5 before 5.1.3, its
85
-
usage would generate an <constant>E_STRICT</constant> warning.
86
-
</simpara>
87
-
</note>
88
81
</sect2>
89
82
90
83
<sect2 xml:id="language.oop5.visiblity-methods">
...
...
@@ -178,7 +171,7 @@ class Foo extends Bar
178
171
}
179
172
}
180
173
181
-
$myFoo = new foo();
174
+
$myFoo = new Foo();
182
175
$myFoo->test(); // Bar::testPrivate
183
176
// Foo::testPublic
184
177
?>
...
...
@@ -188,6 +181,72 @@ $myFoo->test(); // Bar::testPrivate
188
181
</para>
189
182
</sect2>
190
183
184
+
<sect2 xml:id="language.oop5.visiblity-constants">
185
+
<title>Constant Visibility</title>
186
+
<para>
187
+
As of PHP 7.1.0, class constants may be defined as public, private, or
188
+
protected. Constants declared without any explicit visibility
189
+
keyword are defined as public.
190
+
</para>
191
+
<para>
192
+
<example>
193
+
<title>Constant Declaration as of PHP 7.1.0</title>
194
+
<programlisting role="php">
195
+
<![CDATA[
196
+
<?php
197
+
/**
198
+
* Define MyClass
199
+
*/
200
+
class MyClass
201
+
{
202
+
// Declare a public constant
203
+
public const MY_PUBLIC = 'public';
204
+
205
+
// Declare a protected constant
206
+
protected const MY_PROTECTED = 'protected';
207
+
208
+
// Declare a private constant
209
+
private const MY_PRIVATE = 'private';
210
+
211
+
public function foo()
212
+
{
213
+
echo self::MY_PUBLIC;
214
+
echo self::MY_PROTECTED;
215
+
echo self::MY_PRIVATE;
216
+
}
217
+
}
218
+
219
+
$myclass = new MyClass();
220
+
MyClass::MY_PUBLIC; // Works
221
+
MyClass::MY_PROTECTED; // Fatal Error
222
+
MyClass::MY_PRIVATE; // Fatal Error
223
+
$myclass->foo(); // Public, Protected and Private work
224
+
225
+
226
+
/**
227
+
* Define MyClass2
228
+
*/
229
+
class MyClass2 extends MyClass
230
+
{
231
+
// This is public
232
+
function foo2()
233
+
{
234
+
echo self::MY_PUBLIC;
235
+
echo self::MY_PROTECTED;
236
+
echo self::MY_PRIVATE; // Fatal Error
237
+
}
238
+
}
239
+
240
+
$myclass2 = new MyClass2;
241
+
echo MyClass2::MY_PUBLIC; // Works
242
+
$myclass2->foo2(); // Public and Protected work, not Private
243
+
?>
244
+
]]>
245
+
</programlisting>
246
+
</example>
247
+
</para>
248
+
</sect2>
249
+
191
250
<sect2 xml:id="language.oop5.visibility-other-objects">
192
251
<title>Visibility from other objects</title>
193
252
<para>
...
...
@@ -242,7 +301,6 @@ Accessed the private method.
242
301
</example>
243
302
</sect2>
244
303
</sect1>
245
-
246
304
<!-- Keep this comment at the end of the file
247
305
Local variables:
248
306
mode: sgml
249
307