4-8-3.php

php电子书

4-8-3.php<br>接口与组合模拟多重继承<br>
<?
interface UserInterface{ //定义User的接口
	function getname();
}
interface TeacherInterface{ //teacher相关接口
	function getLengthOfService();
}
class User implements UserInterface { //实现UserInterface接口
	private $name = "tom";
	public function getName(){
		return $this->name;
	}
}
class Teacher implements TeacherInterface { //实现TeacherInterface接口
	private $lengthOfService = 5; // 工龄	
	public function getLengthOfService(){
		return $this->lengthOfService;
	}
}
// 继承自User类,同时实现了TeacherInterface接口.
class GraduateStudent extends User implements TeacherInterface {
	private $teacher ;
	public function __construct(){
		$this->teacher = new Teacher();		
	}	
	public function getLengthOfService(){
		return $this->teacher->getLengthOfService();
	}
}
class Act{
	//注意这里的类型提示改成了接口类型
	public static function getUserName(UserInterface $_user){
		echo "Name is " . $_user->getName() ."<br>";
	}
	//这里的类型提示改成了TeacherInterface类型.
	public static function  getLengthOfService(TeacherInterface $_teacher){
		echo "Age is " .$_teacher->getLengthOfService() ."<br>";
	}
}
$graduateStudent = new GraduateStudent();
Act::getUserName($graduateStudent);
Act::getLengthOfService($graduateStudent);
//结果正如我们所要的,实现了有多重身份的一个对象.
?>