1.UML類圖:php
2.PHP代碼:this
<?php /** * Created by PhpStorm. * User: andy * Date: 16-11-23 * Time: 下午7:57 */ interface User { function getName(); } interface Teacher { function getWorkYear(); } class Student implements User { private $name = 'lisi'; function getName() { // TODO: Implement getName() method. echo 'Student name is ' . $this->name . '<br />'; } } class GraduateTeacher implements Teacher { private $work_year = 2; function getWorkYear() { // TODO: Implement getWorkYear() method. echo 'Teacher work year is ' . $this->work_year . '<br />'; } } class GraduateStudent extends Student implements Teacher { private $teacher; public function __construct() { $this->teacher = new GraduateTeacher(); } function getWorkYear() { $this->teacher->getWorkYear(); } } class Test { static function getName(User $student) { $student->getName(); } //當Teacher改爲GraduateTeacher,到後面代碼行的「Test::getWorkYear($lisi);」就會報錯 static function getWorkYear(Teacher $teacher) { $teacher->getWorkYear(); } } $lisi = new GraduateStudent(); $lisi->getName(); $lisi->getWorkYear(); echo '<hr />'; Test::getName($lisi); Test::getWorkYear($lisi); //這裏不會報錯,由於$lisi所屬的類GraduateStudent,實現了Teacher的接口,至關於Teacher身份