【转】PHP通过接口实现多重继承
PHP类虽然是单继承的，但是可以通过其它特殊的方式实现多重继承，比如使用接口实现，只要把类的特征抽象为接口，并通过实现接口的方式让对象有多重身 份，通过这样就可以模拟多重继承了。下面就是一个用接口模拟多重继承的例子，源代码如下：
[*]<?
[*]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.
[*]?>
示例运行结果如下：
Name is tom
Age is 5
页:
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