mysql面向对象抽象类和接口

  1. 抽象类：含有抽象方法的类【abstract 抽象关键词】 
     1 abstract class Usb
 2 {
 3     public function load(){
 4         echo "<p>Usb is loading</p>";
 5     }
 6 
 7     public function start(){
 8         echo "<p>Usb is starting</p>";
 9     }
10 
11     # 抽象方法
12     abstract public function unload();
13 }
14 
15 # 子类
16 class Upan extends Usb
17 {
18     # 调用需先实现unload抽象方法
19     public function unload(){
20         echo "<p>Usb is unloading</p>";
21     }
22 
23     public function jitui(){
24         echo "<p>我喜欢鸡腿</p>";
25     }
26 }
27 
28 $obj = new Upan();
29 $obj->load();

     

  2. 接口：只含有抽象方法的类【interface、abstract 抽象关键词】 
     1 interface Usb
 2 {
 3     public function load();
 4 
 5     public function start();
 6 
 7     public function unload();
 8 }
 9 
10 # 子类
11 class Upan implements Usb
12 {
13     public function load(){
14         echo "<p>Usb is loading</p>";
15     }
16 
17     public function start(){
18         echo "<p>Usb is starting</p>";
19     }
20 
21     public function unload(){
22         echo "<p>Usb is unloading</p>";
23     }
24 }
25 
26 # 调用前需全部实现Usb类中的抽象方法
27 $obj = new Upan();
28 $obj->load();

     

  3. 一个子类实现多个接口 
     1 interface Usb
 2 {
 3     public function load();
 4 
 5     public function start();
 6 
 7     public function unload();
 8 }
 9 
10 interface Usb2
11 {
12     public function run();
13 }
14 
15 # 子类
16 class Upan implements Usb,Usb2
17 {
18     public function load(){
19         echo "<p>Usb is loading</p>";
20     }
21 
22     public function start(){
23         echo "<p>Usb is starting</p>";
24     }
25 
26     public function unload(){
27         echo "<p>Usb is unloading</p>";
28     }
29 
30     public function run(){
31         echo "<p>Usb2 is runing</p>";
32     }
33 }
34 　　　　
35 $obj = new Upan();
36 $obj->load();

     

  4. 接口扩展，只能继承不能实现，一般不常用 
     1 interface Usb
 2 {
 3     public function load();
 4 
 5     public function start();
 6 
 7     public function unload();
 8 }
 9 
10 interface Usb2 extends Usb
11 {
12     public function run();
13 }
14 
15 # 子类
16 class Upan implements Usb2
17 {
18     public function load(){
19         echo "<p>Usb is loading</p>";
20     }
21 
22     public function start(){
23         echo "<p>Usb is starting</p>";
24     }
25 
26     public function unload(){
27         echo "<p>Usb is unloading</p>";
28     }
29 
30     public function run(){
31         echo "<p>Usb2 is runing</p>";
32     }
33 }
34 
35 $obj = new Upan();
36 $obj->load();

     

  5. 多态小实例 
     1 interface Usb
 2 {
 3     public function load();
 4 
 5     public function start();
 6 
 7     public function unload();
 8 }
 9 
10 # 子类
11 class Upan implements Usb
12 {
13     public function load(){
14         echo "<p>Usb is loading</p>";
15     }
16 
17     public function start(){
18         echo "<p>Usb is starting</p>";
19     }
20 
21     public function unload(){
22         echo "<p>Usb is unloading</p>";
23     }
24 
25     public function run(){
26         echo "<p>Usb2 is runing</p>";
27     }
28 }
29 
30 # 非法类
31 class Udisk
32 {
33     public function load(){
34         echo "<p>Usb is loading</p>";
35     }
36 
37     public function start(){
38         echo "<p>Usb is starting</p>";
39     }
40 
41     public function unload(){
42         echo "<p>Usb is unloading</p>";
43     }
44 }
45 
46 # 只有实现了Usb接口中所有方法才能正常调用
47 function useUsb(Usb $o){
48     $o->load();
49     $o->start();
50     $o->unload();
51     echo "<hr>";
52 }
53 
54 $obj = new Upan();
55 $obj2 = new Udisk();
56 useUsb($obj);
57 useUsb($obj2); #失败

     

posted @ 2019-04-14 22:35  yach_yu  阅读(490)  评论(0)  编辑  收藏  举报