PHP/Class/Destructors

Accessing instance-specific data within a destructor

   <source lang="html4strict">

class Database {

   function __destruct() {
        db_close($this->handle); 
   }

}

 </source>
   
  

Class destructors

   <source lang="html4strict">

<?php

  class Book
  {
     private $title;
     private $isbn;
     private $copies;
     function __construct($isbn)
     {

echo "

Book class instance created.

";

     }
     function __destruct()
     {

echo "

Book class instance destroyed.

";

     }
  }
  $book = new Book("1111");

?>

      </source>
   
  

Class with destructors

   <source lang="html4strict">

<?php

   class Book
   {
       private $title;
       private $isbn;
       private $copies;
       function __construct($isbn)
       {

echo "

Book class instance created.

";

       }
       function __destruct()
       {

echo "

Book class instance destroyed.

";

       }  
   }
   $book = new Book("111111111111");

?>

 </source>
   
  

Cleaning Up with the __destruct Method (PHP 5 Only)

   <source lang="html4strict">

<?php class ItemUpdater {

 public function update( Item $item ) {
   print "updating.. ";
   print $item->name;
 }

} class Item {

 public $name = "item";
 private $updater;
 public function setUpdater( ItemUpdater $update ) {
   $this->updater=$update;
 }
 function __destruct() {
   if ( ! empty( $this->updater )) {
     $this->updater->update( $this );
   }
 }

} $item = new Item(); $item->setUpdater( new ItemUpdater() ) ; unset( $item ); ?>

 </source>
   
  

Declaring and Using Object Constructors and Destructors

   <source lang="html4strict">

<?php class cd {

   public $artist;
   public $title;
   protected $tracks;
   private $disk_id;
   public function __construct() {
       $this->disk_id = sha1("cd" . time() . rand());
   }
   public function get_disk_id() {
       return $this->disk_id;
   }

} $mydisk = new cd(); echo $mydisk->get_disk_id(); ?>

 </source>
   
  

Defining an object destructor

   <source lang="html4strict">

class car {

   function __destruct() {
   }

}

 </source>
   
  

destuctor in action

   <source lang="html4strict">

<?php class Person {

   protected $name;    
   private $age;    
   private $id;    
   function __construct( $name, $age ) {
       $this->name = $name;
       $this->age  = $age;
   }
   function setId( $id ) {
       $this->id = $id;
   }
   
   function __destruct() {
       if ( ! empty( $this->id ) ) {
           print "saving person\n";
       }
   }

} $person = new Person( "Joe", 31 ); $person->setId( 111 ); unset( $person ); ?>

      </source>