PHP 抽象类
PHP 抽象类
抽象类是接口和类的混合体。它可以定义功能也可以定义接口。
扩展抽象类的类必须实现抽象类中定义的所有抽象方法。
抽象类的声明方式与类的声明方式相同，但添加了"抽象"关键字。
语法:
abstract class MyAbstract
{
//Methods
}
//And is attached to a class using the extends keyword.
class Myclass extends MyAbstract
{
//class methods
}
示例 1
<?php
abstract class a
{
abstract public function dis1();
abstract public function dis2();
}
class b extends a
{
public function dis1()
{
echo "lidihuo";
}
public function dis2()
{
echo "SSSIT";
}
}
$obj = new b();
$obj->dis1();
$obj->dis2();
?>
输出:
示例 2
<?php
abstract class Animal
{
public $name;
public $age;
public function Describe()
{
return $this->name . ", " . $this->age . " years old";
}
abstract public function Greet();
}
class Dog extends Animal
{
public function Greet()
{
return "Woof!";
}
public function Describe()
{
return parent::Describe() . ", and I'm a dog!";
}
}
$animal = new Dog();
$animal->name = "Bob";
$animal->age = 7;
echo $animal->Describe();
echo $animal->Greet();
?>
输出:
