PHP面向对象程序设计之类与反射API详解

php  /  管理员 发布于 7年前   240

本文实例讲述了PHP面向对象程序设计之类与反射API。分享给大家供大家参考，具体如下：

了解类

class_exists验证类是否存在

doSpeak();?>

get_class 检查对象的类 instanceof 验证对象是否属于某个类

get_class_methods 得到类中所有的方法列表,只获取public的方法，protected，private的方法获取不到。默认的就是public。

output:

Array(  [0] => __construct  [1] => getPlayLength  [2] => getSummaryLine  [3] => getProducerFirstName  [4] => getProducerMainName  [5] => setDiscount  [6] => getDiscount  [7] => getTitle  [8] => getPrice  [9] => getProducer)

更多验证

$method(); // invoke the methodif ( in_array( $method, get_class_methods( $product ) ) ) {  print $product->$method(); // invoke the method}if ( is_callable( array( $product, $method) ) ) {  print $product->$method(); // invoke the method}if ( method_exists( $product, $method ) ) {  print $product->$method(); // invoke the method}print_r( get_class_vars( 'CdProduct' ) );if ( is_subclass_of( $product, 'ShopProduct' ) ) {  print "CdProduct is a subclass of ShopProduct\n";}if ( is_subclass_of( $product, 'incidental' ) ) {  print "CdProduct is a subclass of incidental\n";}if ( in_array( 'incidental', class_implements( $product )) ) {  print "CdProduct is an interface of incidental\n";}?>

output:

titletitletitletitleArray(  [coverUrl] =>)CdProduct is a subclass of ShopProductCdProduct is a subclass of incidentalCdProduct is an interface of incidental

__call方法

thirdpartyShop = new OtherShop();  }  function __call( $method, $args ) { // 当调用未命名方法时执行call方法    if ( method_exists( $this->thirdpartyShop, $method ) ) {      return $this->thirdpartyShop->$method( );    }  }}$d = new Delegator();$d->thing();?>

output:

thing

传参使用

thirdpartyShop = new OtherShop();  }  function __call( $method, $args ) {    if ( method_exists( $this->thirdpartyShop, $method ) ) {      return call_user_func_array(array( $this->thirdpartyShop,  $method ), $args );    }  }}$d = new Delegator();$d->andAnotherThing( "hi", "hello" );?>

output:

another thing (hi, hello)

反射API

fullshop.php

title       = $title;    $this->producerFirstName = $firstName;    $this->producerMainName = $mainName;    $this->price       = $price;  }  public function getProducerFirstName() {    return $this->producerFirstName;  }  public function getProducerMainName() {    return $this->producerMainName;  }  public function setDiscount( $num ) {    $this->discount=$num;  }  public function getDiscount() {    return $this->discount;  }  public function getTitle() {    return $this->title;  }  public function getPrice() {    return ($this->price - $this->discount);  }  public function getProducer() {    return "{$this->producerFirstName}".        " {$this->producerMainName}";  }  public function getSummaryLine() {    $base = "{$this->title} ( {$this->producerMainName}, ";    $base .= "{$this->producerFirstName} )";    return $base;  }}class CdProduct extends ShopProduct {  private $playLength = 0;  public function __construct(  $title, $firstName,  $mainName, $price, $playLength=78 ) {    parent::__construct(  $title, $firstName,    $mainName, $price );    $this->playLength = $playLength;  }  public function getPlayLength() {    return $this->playLength;  }  public function getSummaryLine() {    $base = parent::getSummaryLine();    $base .= ": playing time - {$this->playLength}";    return $base;  }}class BookProduct extends ShopProduct {  private $numPages = 0;  public function __construct(  $title, $firstName,  $mainName, $price, $numPages ) {    parent::__construct(  $title, $firstName,    $mainName, $price );    $this->numPages = $numPages;  }  public function getNumberOfPages() {    return $this->numPages;  }  public function getSummaryLine() {    $base = parent::getSummaryLine();    $base .= ": page count - {$this->numPages}";    return $base;  }  public function getPrice() {    return $this->price;  }}/*$product1 = new CdProduct("cd1", "bob", "bobbleson", 4, 50 );print $product1->getSummaryLine()."\n";$product2 = new BookProduct("book1", "harry", "harrelson", 4, 30 );print $product2->getSummaryLine()."\n";*/?>

output:

Class [  class CdProduct extends ShopProduct ] { @@ D:\xampp\htdocs\popp-code\5\fullshop.php 53-73 - Constants [0] { } - Static properties [0] { } - Static methods [0] { } - Properties [2] {  Property [  private $playLength ]  Property [  protected $price ] } - Methods [10] {  Method [  public method __construct ] {   @@ D:\xampp\htdocs\popp-code\5\fullshop.php 56 - 61   - Parameters [5] {    Parameter #0 [  $title ]    Parameter #1 [  $firstName ]    Parameter #2 [  $mainName ]    Parameter #3 [  $price ]    Parameter #4 [  $playLength = 78 ]   }  }  Method [  public method getPlayLength ] {   @@ D:\xampp\htdocs\popp-code\5\fullshop.php 63 - 65  }  Method [  public method getSummaryLine ] {   @@ D:\xampp\htdocs\popp-code\5\fullshop.php 67 - 71  }  Method [  public method getProducerFirstName ] {   @@ D:\xampp\htdocs\popp-code\5\fullshop.php 17 - 19  }  Method [  public method getProducerMainName ] {   @@ D:\xampp\htdocs\popp-code\5\fullshop.php 21 - 23  }  Method [  public method setDiscount ] {   @@ D:\xampp\htdocs\popp-code\5\fullshop.php 25 - 27   - Parameters [1] {    Parameter #0 [  $num ]   }  }  Method [  public method getDiscount ] {   @@ D:\xampp\htdocs\popp-code\5\fullshop.php 29 - 31  }  Method [  public method getTitle ] {   @@ D:\xampp\htdocs\popp-code\5\fullshop.php 33 - 35  }  Method [  public method getPrice ] {   @@ D:\xampp\htdocs\popp-code\5\fullshop.php 37 - 39  }  Method [  public method getProducer ] {   @@ D:\xampp\htdocs\popp-code\5\fullshop.php 41 - 44  } }}

点评：把类看的透彻的一塌糊涂，比var_dump强多了。哪些属性，继承了什么类。类中的方法哪些是自己的，哪些是重写的，哪些是继承的，一目了然。

查看类数据

getName(); if ( $class->isUserDefined() ) {  $details .= "$name is user defined\n"; } if ( $class->isInternal() ) {  $details .= "$name is built-in\n"; } if ( $class->isInterface() ) {  $details .= "$name is interface\n"; } if ( $class->isAbstract() ) {  $details .= "$name is an abstract class\n"; } if ( $class->isFinal() ) {  $details .= "$name is a final class\n"; } if ( $class->isInstantiable() ) {  $details .= "$name can be instantiated\n"; } else {  $details .= "$name can not be instantiated\n"; } return $details;}$prod_class = new ReflectionClass( 'CdProduct' );print classData( $prod_class );?>

output:

CdProduct is user defined
CdProduct can be instantiated

查看方法数据

getMethods();foreach ( $methods as $method ) { print methodData( $method ); print "\n----\n";}function methodData( ReflectionMethod $method ) { $details = ""; $name = $method->getName(); if ( $method->isUserDefined() ) {  $details .= "$name is user defined\n"; } if ( $method->isInternal() ) {  $details .= "$name is built-in\n"; } if ( $method->isAbstract() ) {  $details .= "$name is abstract\n"; } if ( $method->isPublic() ) {  $details .= "$name is public\n"; } if ( $method->isProtected() ) {  $details .= "$name is protected\n"; } if ( $method->isPrivate() ) {  $details .= "$name is private\n"; } if ( $method->isStatic() ) {  $details .= "$name is static\n"; } if ( $method->isFinal() ) {  $details .= "$name is final\n"; } if ( $method->isConstructor() ) {  $details .= "$name is the constructor\n"; } if ( $method->returnsReference() ) {  $details .= "$name returns a reference (as opposed to a value)\n"; } return $details;}?>

output:

__construct is user defined__construct is public__construct is the constructor----getPlayLength is user definedgetPlayLength is public----getSummaryLine is user definedgetSummaryLine is public----getProducerFirstName is user definedgetProducerFirstName is public----getProducerMainName is user definedgetProducerMainName is public----setDiscount is user definedsetDiscount is public----getDiscount is user definedgetDiscount is public----getTitle is user definedgetTitle is public----getPrice is user definedgetPrice is public----getProducer is user definedgetProducer is public

获取构造函数参数情况

getMethod( "__construct" );$params = $method->getParameters();foreach ( $params as $param ) {  print argData( $param )."\n";}function argData( ReflectionParameter $arg ) { $details = ""; $declaringclass = $arg->getDeclaringClass(); $name = $arg->getName(); $class = $arg->getClass(); $position = $arg->getPosition(); $details .= "\$$name has position $position\n"; if ( ! empty( $class ) ) {  $classname = $class->getName();  $details .= "\$$name must be a $classname object\n"; } if ( $arg->isPassedByReference() ) {  $details .= "\$$name is passed by reference\n"; } if ( $arg->isDefaultValueAvailable() ) {  $def = $arg->getDefaultValue();  $details .= "\$$name has default: $def\n"; } if ( $arg->allowsNull() ) {  $details .= "\$$name can be null\n"; } return $details;}?>

output:

$title has position 0$title can be null$firstName has position 1$firstName can be null$mainName has position 2$mainName can be null$price has position 3$price can be null$playLength has position 4$playLength has default: 78$playLength can be null

更多关于PHP相关内容感兴趣的读者可查看本站专题：《php面向对象程序设计入门教程》、《PHP基本语法入门教程》、《PHP运算与运算符用法总结》、《PHP网络编程技巧总结》、《PHP数组(Array)操作技巧大全》、《php字符串(string)用法总结》、《php+mysql数据库操作入门教程》及《php常见数据库操作技巧汇总》

希望本文所述对大家PHP程序设计有所帮助。

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