Community Learn Tools Library Leisure
search
English
Home > php教程 > PHP开发 > Detailed explanation of PHP object-oriented programming and reflection API

Detailed explanation of PHP object-oriented programming and reflection API

高洛峰
Release： 2016-12-30 10:14:23
Original
1352 people have browsed it

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

<?php
// TaskRunner.php
$classname = "Task";
$path = "tasks/{$classname}.php";
if ( ! file_exists( $path ) ) {
  throw new Exception( "No such file as {$path}" ); //抛出异常,类文件不存在
}
require_once( $path );
$qclassname = "tasks\\$classname";
if ( ! class_exists( $qclassname ) ) {
  throw new Exception( "No such class as $qclassname" ); //抛出异常,类不存在Fatal error: Uncaught exception &#39;Exception&#39; with message &#39;No such class as tasks\Task&#39;
Stack trace:
#0 {main}
}
$myObj = new $qclassname();
$myObj->doSpeak();
?>
Copy after login

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

<?php
class CdProduct {}
function getProduct() {
  return new CdProduct(  "Exile on Coldharbour Lane",
                "The", "Alabama 3", 10.99, 60.33 ); // 返回一个类对象
}
$product = getProduct();
if ( get_class( $product ) == &#39;CdProduct&#39; ) {
  print "\$product is a CdProduct object\n";
}
?>
<?php
class CdProduct {}
function getProduct() {
  return new CdProduct(  "Exile on Coldharbour Lane",
                "The", "Alabama 3", 10.99, 60.33 );
}
$product = getProduct();
if ( $product instanceof CdProduct ) {
  print "\$product is a CdProduct object\n";
}
?>
Copy after login

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。

<?php
class CdProduct {
  function __construct() { }
  function getPlayLength() { }
  function getSummaryLine() { }
  function getProducerFirstName() { }
  function getProducerMainName() { }
  function setDiscount() { }
  function getDiscount() { }
  function getTitle() { }
  function getPrice() { }
  function getProducer() { }
}
print_r( get_class_methods( &#39;CdProduct&#39; ) );
?>
Copy after login

output:

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

更多验证

<?php
class ShopProduct {}
interface incidental {};
class CdProduct extends ShopProduct implements incidental {
  public $coverUrl;
  function __construct() { }
  function getPlayLength() { }
  function getSummaryLine() { }
  function getProducerFirstName() { }
  function getProducerMainName() { }
  function setDiscount() { }
  function getDiscount() { }
  function getTitle() { return "title\n"; }
  function getPrice() { }
  function getProducer() { }
}
function getProduct() {
  return new CdProduct();
}
$product = getProduct(); // acquire an object
$method = "getTitle";   // define a method name
print $product->$method(); // invoke the method
if ( 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( &#39;CdProduct&#39; ) );
if ( is_subclass_of( $product, &#39;ShopProduct&#39; ) ) {
  print "CdProduct is a subclass of ShopProduct\n";
}
if ( is_subclass_of( $product, &#39;incidental&#39; ) ) {
  print "CdProduct is a subclass of incidental\n";
}
if ( in_array( &#39;incidental&#39;, class_implements( $product )) ) {
  print "CdProduct is an interface of incidental\n";
}
?>
Copy after login

output:

title
title
title
title
Array
(
  [coverUrl] =>
)
CdProduct is a subclass of ShopProduct
CdProduct is a subclass of incidental
CdProduct is an interface of incidental
Copy after login

__call方法

<?php
class OtherShop {
  function thing() {
    print "thing\n";
  }
  function andAnotherthing() {
    print "another thing\n";
  }
}
class Delegator {
  private $thirdpartyShop;
  function __construct() {
    $this->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();
?>
Copy after login

output:

thing

传参使用

<?php
class OtherShop {
  function thing() {
    print "thing\n";
  }
  function andAnotherthing( $a, $b ) {
    print "another thing ($a, $b)\n";
  }
}
class Delegator {
  private $thirdpartyShop;
  function __construct() {
    $this->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" );
?>
Copy after login

output:

another thing (hi, hello)

反射API

fullshop.php

<?php
class ShopProduct {
  private $title;
  private $producerMainName;
  private $producerFirstName;
  protected $price;
  private $discount = 0;
  public function __construct(  $title, $firstName,
              $mainName, $price ) {
    $this->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";
*/
?>
<?php
require_once "fullshop.php";
$prod_class = new ReflectionClass( &#39;CdProduct&#39; );
Reflection::export( $prod_class );
?>
Copy after login

output:

Class [ <user> 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 [ <default> private $playLength ]
  Property [ <default> protected $price ]
 }
 - Methods [10] {
  Method [ <user, overwrites ShopProduct, ctor> public method __construct ] {
   @@ D:\xampp\htdocs\popp-code\5\fullshop.php 56 - 61
   - Parameters [5] {
    Parameter #0 [ <required> $title ]
    Parameter #1 [ <required> $firstName ]
    Parameter #2 [ <required> $mainName ]
    Parameter #3 [ <required> $price ]
    Parameter #4 [ <optional> $playLength = 78 ]
   }
  }
  Method [ <user> public method getPlayLength ] {
   @@ D:\xampp\htdocs\popp-code\5\fullshop.php 63 - 65
  }
  Method [ <user, overwrites ShopProduct, prototype ShopProduct> public method getSummaryLine ] {
   @@ D:\xampp\htdocs\popp-code\5\fullshop.php 67 - 71
  }
  Method [ <user, inherits ShopProduct> public method getProducerFirstName ] {
   @@ D:\xampp\htdocs\popp-code\5\fullshop.php 17 - 19
  }
  Method [ <user, inherits ShopProduct> public method getProducerMainName ] {
   @@ D:\xampp\htdocs\popp-code\5\fullshop.php 21 - 23
  }
  Method [ <user, inherits ShopProduct> public method setDiscount ] {
   @@ D:\xampp\htdocs\popp-code\5\fullshop.php 25 - 27
   - Parameters [1] {
    Parameter #0 [ <required> $num ]
   }
  }
  Method [ <user, inherits ShopProduct> public method getDiscount ] {
   @@ D:\xampp\htdocs\popp-code\5\fullshop.php 29 - 31
  }
  Method [ <user, inherits ShopProduct> public method getTitle ] {
   @@ D:\xampp\htdocs\popp-code\5\fullshop.php 33 - 35
  }
  Method [ <user, inherits ShopProduct> public method getPrice ] {
   @@ D:\xampp\htdocs\popp-code\5\fullshop.php 37 - 39
  }
  Method [ <user, inherits ShopProduct> public method getProducer ] {
   @@ D:\xampp\htdocs\popp-code\5\fullshop.php 41 - 44
  }
 }
}
Copy after login

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

<?php
require_once("fullshop.php");
function classData( ReflectionClass $class ) {
 $details = "";
 $name = $class->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( &#39;CdProduct&#39; );
print classData( $prod_class );
?>
Copy after login

output:

CdProduct is user defined
CdProduct can be instantiated

查看方法数据

<?php
require_once "fullshop.php";
$prod_class = new ReflectionClass( &#39;CdProduct&#39; );
$methods = $prod_class->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;
}
?>
Copy after login

output:

__construct is user defined
__construct is public
__construct is the constructor
----
getPlayLength is user defined
getPlayLength is public
----
getSummaryLine is user defined
getSummaryLine is public
----
getProducerFirstName is user defined
getProducerFirstName is public
----
getProducerMainName is user defined
getProducerMainName is public
----
setDiscount is user defined
setDiscount is public
----
getDiscount is user defined
getDiscount is public
----
getTitle is user defined
getTitle is public
----
getPrice is user defined
getPrice is public
----
getProducer is user defined
getProducer is public
Copy after login

获取构造函数参数情况

<?php
require_once "fullshop.php";
$prod_class = new ReflectionClass( &#39;CdProduct&#39; );
$method = $prod_class->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;
}
?>
Copy after login

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
Copy after login

   

希望本文所述对大家PHP程序设计有所帮助。

更多PHP面向对象程序设计之类与反射API详解相关文章请关注PHP中文网！

Related labels：
PHP 面向对象 类 反射API
source：php.cn
Previous article：Yii2 framework study notes (7) -- gii and GridView Next article：PHP+Ajax asynchronous communication implements username and email verification to verify whether it has been registered (2 methods to implement)
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Latest Articles by Author
Latest Issues
function_exists() cannot determine the custom function Function test () {return true;} if (function_exists ('test')) {echo "test is function...
From 2024-04-29 11:01:01
0
3
2248
How to display the mobile version of Google Chrome Hello teacher, how can I change Google Chrome into a mobile version?
From 2024-04-23 00:22:19
0
11
2387
The child window operates the parent window, but the output does not respond. The first two sentences are executable, but the last sentence cannot be implemented.
From 2024-04-19 15:37:47
0
1
1997
There is no output in the parent window document.onclick = function(){ window.opener.document.write('I am the output of the child ...
From 2024-04-18 23:52:34
0
1
1883
Where is the courseware about CSS mind mapping? Courseware
From 2024-04-16 10:10:18
0
0
1952
Related Topics
More>
Popular Recommendations
Popular Tutorials
More>
Related Tutorials
Popular Recommendations
Latest courses
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template