PHPOOP - Access Modifiers
PHP - Access Modifiers
Properties and methods can have access modifiers (or visibility keywords) which control where they can be accessed.
In PHP, there are three access modifiers:
public- the property or method can be accessed from everywhere. This is defaultprotected- the property or method can be accessed within the class and by classes derived from that classprivate- the property or method can ONLY be accessed within the same class where they are defined
Note: If no acces modifier is specified, it will be set topublic.
Public Access Modifier
Thepublic access modifier allows class properties or methods to be accessed from everywhere.
In the following example, the $name property and the get_details() method are accessible from outside the class.
Example
class Fruit {
public $name;
public function get_details() {
echo "Name: " . $this->name . ".";
}
}
$apple = new Fruit();
$apple->name = "Apple"; // Can be accessed directly
$apple->get_details();
?>
Private Access Modifier
Theprivate access modifier allows class properties or methods ONLY to be accessed within the same class where they are defined.
In the following example, the $name property is private and cannot be accessed directcly.
Example
class Fruit {
private $name;
public function get_details() {
echo "Name: " . $this->name . ".";
}
}
$apple = new Fruit();
$apple->name = "Apple"; // Error: Cannot access private property
$apple->get_details();
?>
Protected Access Modifier
Theprotected access modifier allows class properties or methods to be accessed within the class and by classes derived from that class (child classes).
In the following example, the $name property is protected and cannot be accessed directcly.
Example
class Fruit {
private $name;
public function get_details() {
echo "Name: " . $this->name . ".";
}
}
$apple = new Fruit();
$apple->name = "Apple"; // Error: Cannot access protected property
$apple->get_details();
?>
In the following example, the $name property is protected and cannot be accessed directcly from outside the class, but it will be accessible within the Apple subclass (child class).
Example
class Fruit {
protected $name;
public function setType($name) {
$this->name = $name;
}
}
class Apple extends Fruit {
public function getType() {
echo "Name: " . $this->name . ".";
}
}
$apple = new Apple();
$apple->setType("Apple");
//echo $apple->name; // Error: Cannot access protected property
echo $apple->getType(); // Output: Name: Apple.
?>
