<?php
class Fruit {
public $name;
public $color;
public function __construct($name, $color) {
$this->name = $name;
$this->color = $color;
}
public function intro() {
echo "The fruit is {$this->name} and the color is {$this->color}.";
}
}
// Strawberry is inherited from Fruit
class Strawberry extends Fruit {
public function message() {
echo "Am I a fruit or a berry? ";
}
}
$strawberry = new Strawberry("Strawberry", "red");
$strawberry->message();
$strawberry->intro();
?>
<?php
class Fruit {
public $name;
public $color;
public function construct($name, $color) {
$this->name = $name;
$this->color = $color;
}
protected function intro() {
echo "The fruit is {$this->name} and the color is {$this->color}.";
}
}
class Strawberry extends Fruit {
public function message() {
echo "Am I a fruit or a berry? ";
}
}
// Try to call all three methods from outside class
$strawberry = new Strawberry("Strawberry", "red"); // OK. construct() is public
$strawberry->message(); // OK. message() is public
$strawberry->intro(); // ERROR. intro() is protected
?>
<?php
class Fruit {
public $name;
public $color;
public function construct($name, $color) {
$this->name = $name;
$this->color = $color;
}
protected function intro() {
echo "The fruit is {$this->name} and the color is {$this->color}.";
}
}
class Strawberry extends Fruit {
public function message() {
echo "Am I a fruit or a berry? ";
// Call protected method from within derived class - OK
$this -> intro();
}
}
$strawberry = new Strawberry("Strawberry", "red"); // OK. construct() is public
$strawberry->message(); // OK. message() is public and it calls intro() (which is protected) from within the derived class
?>
<?php
class Fruit {
public $name;
public $color;
public function construct($name, $color) {
$this->name = $name;
$this->color = $color;
}
public function intro() {
echo "The fruit is {$this->name} and the color is {$this->color}.";
}
}
class Strawberry extends Fruit {
public $weight;
public function construct($name, $color, $weight) {
$this->name = $name;
$this->color = $color;
$this->weight = $weight;
}
public function intro() {
echo "The fruit is {$this->name}, the color is {$this->color}, and the weight is {$this->weight} gram.";
}
}
$strawberry = new Strawberry("Strawberry", "red", 50);
$strawberry->intro();
?>
<?php
final class Fruit {
// some code
}
// will result in error
class Strawberry extends Fruit {
// some code
}
?>
次の例は、メソッドのオーバーライドを防ぐ方法を示しています。
例
<?php
class Fruit {
final public function intro() {
// some code
}
}
class Strawberry extends Fruit {
// will result in error
public function intro() {
// some code
}
}
?>
