4-8-2.php

php电子书

4-8-2.php<br>组合<br>
<?
class User{
	private $name = "tom";
	public function getName(){
		return $this->name;
	}
}
class Teacher{
	private $lengthOfService = 5; // 工龄	
	public function getLengthOfService(){
		return $this->lengthOfService;
	}
}
class GraduateStudent extends User {
	private $teacher ;
	public function __construct(){
		$this->teacher = new Teacher();		
	}	
	public function getLengthOfService(){
		return $this->teacher->getLengthOfService();
	}
}
class Act{
	public static function getUserName(User $_user){
		echo $_user->getName();
	}
	public static function  getLengthOfService(Teacher $_teacher){
		echo $_teacher->getLengthOfService();
	}
}
$graduateStudent = new GraduateStudent();
Act::getUserName($graduateStudent);
Act::getLengthOfService($graduateStudent);

?>