PHP/Class/Objects

Comparing Objects with == and ===

 
<?php
    class Employee { }
    $Bob = new Employee( );
    $Joe = clone $Bob;
    print (int)($Bob == $Joe) . "\n";
    print (int)($Joe === $Joe) . "\n";
    class Employee {
            public function __construct( ) {
                    $this->myself = $this;
            }
    }
    $Bob = new Employee( );
    $Joe = clone $Bob;
    print (int)($Bob == $Joe) . "\n";
    print (int)($Bob === $Joe) . "\n";
    
?>

Create a new class and create an instance then use its property and method

 
<?php
class Dog
{
  var $name;
  function bark()
  {
    print "Woof!";
  }
}
$pooch = new Dog;
$pooch -> name = "new name";
print $pooch -> name . " says ";
$pooch -> bark();
?>

Creating a new object and assigning it to a variable

 
<?php
Class Cat {
  // Constructor
  function __constructor(  ) {
  }
  // The cat meows
  function meow(  ) {
    echo "Meow...";
  }
  // The cat eats
  function eat(  ) {
    echo "*eats*";
  }
  // The cat purrs
  function purr(  ) {
    echo "*Purr...*";
  }
}
$myCat=new Cat;
?>

Object Initialization

 
<?php
class foo {
    function do_foo() {
        echo "Doing foo.";
    }
}
$bar = new foo;
$bar->do_foo();
?>

Object Overloading

 
<?php
class Data {
    private $data = array();
    public function __set($name, $value) {
        $this->data[$name] = $value;
    }
    public function __get($name) {
        if (isset($this->data[$name])) { return $this->data[$name]; }
    }
    public function __isset($name) {
        return isset($this->data[$name]);
    }
    public function __unset($name) {
        unset($this->data[$name]);
    }
}
$data = new Data();
$data->name = "F";
echo "<p>The data value of "name" is {$data->name}</p>";
unset($data->name);
echo "<p>The value is ", isset($data->name) ? "" : "not ", "set.</p>";
?>

Object Properties

 
<?
class Item {
  var $name = "item";
}
$obj1 = new Item();
$obj2 = new Item();
$obj1->name = "widget 5442";
print "$obj1->name<br />";
print "$obj2->name<br />";
?>

Objects Within Objects

 
<?
    class DogTag {
            public $Words;
    }
    class Dog {
            public $Name;
            public $DogTag;
            public function bark( ) {
                    print "Woof!\n";
            }
    }
    $poppy = new Poodle;
    $poppy->Name = "Poppy";
    $poppy->DogTag = new DogTag;
    $poppy->DogTag->Words = "call 555-1234";
?>

Object Type Information

 
<?
    class Dog {
            public $Name;
            private function getName( ) {
                    return $this->Name;
            }
    }
    class Poodle extends Dog {
            public function bark( ) {
                    print ""Woof", says " . $this->getName( );
            }
    }
    $poppy = new Poodle;
    $poppy->Name = "Poppy";
    $poppy->bark( );
    if ($poppy instanceof poodle) { }
    if ($poppy instanceof dog) { }
?>