Abstract classes and interfaces
In PHP, abstract classes can be declared through the abstract keyword. Sometimes we need a class to have certain public methods. In this case, we can use interface technology
1, create an animal class
##Animal.class.php code is as follows:
<?php
/**
* Created by PhpStorm.
* User: Administrator
* Date: 2018/3/3 0003
* Time: 下午 2:13
*/
abstract class Animal{
public $gender; //性别
public $size; //尺寸
public function __construct($gender,$size){
$this->gender=$gender;
$this->size=$size;
}
//限制非抽象类都需要调用此方法
abstract protected function getGender();
//final要求每个子类必须存在该方法并且不能重写
final public function getSize(){
return $this->size;
}
}2, create a dog class
Dog.class.php code is as follows:<?php
/**
* Created by PhpStorm.
* User: Administrator
* Date: 2018/3/3 0003
* Time: 下午 2:20
*/
header('content-type:text/html;charset=utf8');
require './Animal.class.php';
class Dog extends Animal {
/**
* @return mixed
*/
public function getGender()
{
return "'$this->gender'狗";
}
}
$dog=new Dog('公','大');
echo $dog->getSize();
echo $dog->getGender();
The running results are as follows:
##3, create a cat classCat.class.php code is as follows:
<?php
/**
* Created by PhpStorm.
* User: Administrator
* Date: 2018/3/3 0003
* Time: 下午 2:22
*/
header('content-type:text/html;charset=utf8');
require './Animal.class.php';
class Cat extends Animal {
public function getGender()
{
return "'$this->gender'猫";
}
}
$dog=new Cat('母','小');
echo $dog->getSize();
echo $dog->getGender();The running results are as follows:
Create the interface.php file, the code is as follows:
<?php
/**
* Created by PhpStorm.
* User: Administrator
* Date: 2018/3/3 0003
* Time: 下午 2:34
*/
header('content-type:text/html;charset=utf8');
//定义usb接口
interface usb{
public function connect(); //连接
public function transfer(); //传输
public function disconnect(); //断开
}
class mp3 implements usb{
public function connect()
{
// TODO: Implement connect() method.
echo "连接...<br>";
}
public function transfer()
{
// TODO: Implement transfer() method.
echo "传输...<br>";
}
public function disconnect()
{
// TODO: Implement disconnect() method.
echo "断开...<br>";
}
}
$mp3=new mp3();
$mp3->connect();
$mp3->transfer();
$mp3->disconnect(); operation result:
