PHP面向对象之旅：一个接口实例，很好的例子

01

<?

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/*

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* 定义了 User接口.

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* 和子类 NormalUser,VipUser,InnerUser

05

*/

06

//User接口,定义了三个抽象方法.

07

interface

User{

08

public

function

getName();

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public

function

setName(

$_name

);

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public

function

getDiscount();

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}

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abstract

class

AbstractUser

implements

User{

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private

$name

=

""

;

//名字

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protected

$discount

=0; 

//折扣

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protected

$grade

=

""

; 

//级别

16

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public

function

__construct(

$_name

){

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$this

->setName(

$_name

);

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}

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public

function

getName(){

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return

$this

->name;

22

}

23

public

function

setName(

$_name

){

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$this

->name =

$_name

;

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}

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public

function

getDiscount(){

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return

$this

->discount;

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}

29

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public

function

getGrade(){

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return

$this

->grade;

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}

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}

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class

NormalUser

extends

AbstractUser  {   

35

protected

$discount

=1.0;

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protected

$grade

=

"NormalUser"

;

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}

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class

VipUser

extends

AbstractUser {

39

protected

$discount

=0.8;

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protected

$grade

=

"VipUser"

;

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}

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class

InnerUser

extends

AbstractUser {

43

protected

$discount

=0.7;

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protected

$grade

=

"InnerUser"

;

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}

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?>

01

<?

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/*与产品相关的类放.*/

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Interface Product{

//定义产品接口

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public

function

getProductName();

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public

function

getProductPrice();

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}

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interface

Book

extends

Product {

// book是产品的一个分类

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public

function

getAuthor();

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}

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class

BookOnline

implements

Book{

// 定义book类.

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private

$productName

; 

// 产品名

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private

$productPrice

;

// 产品价格

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private

$author

; 

//作者

14

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public

function

__construct(

$_bookName

){

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$this

->productName =

$_bookName

;

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//这里放置相关初始化的代码.

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//与数据库关联的代码.

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}

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public

function

getProductName(){

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return

$this

->productName;

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}

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public

function

getProductPrice(){

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//这里从数据库读取价格.

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//假设价格是 100元.

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$this

->productPrice =100;

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return

$this

->productPrice;

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}

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public

function

getAuthor(){

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//从数据库里面取值.

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return

$this

->author;

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}  

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}

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?>

01

<?

02

include_once

(

"User.php"

);

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include_once

(

"Product.php"

);

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//买了产品到底多少钱呢?

05

class

ProductSettle{

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public

static

function

finalPrice(User

$_user

,Product

$_product

,

$number

=1){

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$price

=

$_user

->getDiscount() *

$_product

->getProductPrice() *

$number

;

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return

$price

;

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}

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}

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?>

01

<?

02

include_once

(

"./class/User.php"

);

03

include_once

(

"./class/Product.php"

);

04

include_once

(

"./class/ProductSettle.php"

);

05

$number

=10;

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$book

=

new

BookOnline(

"设计模式"

);

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$user

=

new

NormalUser(

"Tom"

);

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$price

=ProductSettle::finalPrice(

$user

,

$book

,

$number

);

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$str

= 

"您好，尊敬的用户 "

.

$user

->getName() .

" <br>"

;

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$str

.=

"您的级别是 "

.

$user

->getGrade() .

", <br>"

;

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$str

.=

"您的折扣是 "

.

$user

->getDiscount() .

"<br>"

;

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$str

.=

"购买 $number 本 《 "

.

$book

->getProductName() ;

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$str

.= 

"》的价格是 $price <br><br>"

;

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echo

$str

;

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$user

=

new

vipUser(

"Tom"

);

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$price

=ProductSettle::finalPrice(

$user

,

$book

,

$number

);

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$str

= 

"您好，尊敬的用户 "

.

$user

->getName() .

" <br>"

;

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$str

.=

"您的级别是 "

.

$user

->getGrade() .

", <br>"

;

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$str

.=

"您的折扣是 "

.

$user

->getDiscount() .

"<br>"

;

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$str

.=

"购买 $number 本 《 "

.

$book

->getProductName() ;

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$str

.= 

"》的价格是 $price <br><br>"

;

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echo

$str

;

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$user

=

new

InnerUser(

"Tom"

);

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$price

=ProductSettle::finalPrice(

$user

,

$book

,

$number

);

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$str

= 

"您好，尊敬的用户 "

.

$user

->getName() .

" <br>"

;

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$str

.=

"您的级别是 "

.

$user

->getGrade() .

", <br>"

;

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$str

.=

"您的折扣是 "

.

$user

->getDiscount() .

"<br>"

;

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$str

.=

"购买 $number 本 《 "

.

$book

->getProductName() ;

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$str

.= 

"》的价格是 $price <br><br>"

;

30

echo

$str

;

31

?>