PHP Handbuch
Zurück | Kapitel 18. Classes and Objects (PHP 5) | Weiter

# Visibility

The visibility of a property or method can be defined by prefixing the declaration with the keywords: public, protected or private. Public declared items can be acessed everywhere. Protected limits access to inherited classes (and to the class that defines the item). Private limits visiblity only to the class that defines the item.

## Members Visibility

Class members must be defined with public, private, or protected.

Beispiel 18-3. Member declaration

`<?php
class MyClass {
public $public = "MyClass::public!\n";
protected $protected = "MyClass::Protected!\n";
protected $protected2 = "MyClass::Protected2!\n";
private $private = "MyClass::private!\n";
function printHello() {
print "MyClass::printHello() " . $this->private;
print "MyClass::printHello() " . $this->protected;
print "MyClass::printHello() " . $this->protected2;
}
}
class MyClass2 extends MyClass {
protected $protected = "MyClass2::protected!\n";
function printHello() {
MyClass::printHello();
print "MyClass2::printHello() " . $this->public;
print "MyClass2::printHello() " . $this->protected;
print "MyClass2::printHello() " . $this->protected2;
/* Will result in a Fatal Error: */
//print "MyClass2::printHello() " . $this->private; /* Fatal Error */
}
}
$obj = new MyClass();
print "Main:: " . $obj->public;
//print $obj->private; /* Fatal Error */
//print $obj->protected; /* Fatal Error */
//print $obj->protected2; /* Fatal Error */
$obj->printHello(); /* Should print */
$obj2 = new MyClass2();
print "Main:: " . $obj2->private; /* Undefined */
//print $obj2->protected; /* Fatal Error */
//print $obj2->protected2; /* Fatal Error */
$obj2->printHello();
?>`

> Anmerkung: The use PHP 4 use of declaring a variable with the keyword 'var' is no longer valid for PHP 5 objects. For compatiblity a variable declared in php will be assumed with public visiblity, and a `E_STRICT` warning will be issued.

## Method Visibility

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