PHP/Class/Class Method

Accessing the Attributes of a Class by Using Functions

<?php
  class employee{
      var $emp_code;
      var $name;
      var $address;
      var $department;
      var $sex;
      var $date_of_birth;
      var $salary;
      function showsalary () {
         echo "Your salary is :",$this->salary," \n";
      }
  }
  $dave = new employee;
  $dave->emp_code="8";
  $dave->name="Dave";
  $dave->address="Apartment 1";
  $dave->department="Admin Development";
  $dave->sex="Male";
  $dave->salary="70";
  $dave->date_of_birth="15-09-1977";
  $dave->showsalary();
?>

Access properties

 
<?php
 
  class Bird
  {
    function __construct($name="No-name", $breed="unknown", $price = 15)
    {
      $this->name = $name;
      $this->breed = $breed;
      $this->price = $price;
    }    
    
    function setName($name)
    {
      $this->name = $name;
    }    
    
    function setBreed($breed)
    {
      $this->breed = $breed;
    }    
    
    function setPrice($price)
    {
      $this->price = $price < 0 ? 0 : $price;
    }
    
    function getName()
    {
      return $this->name;
    }    
    
    function getBreed()
    {
      return $this->breed;
    }    
    
    function getPrice()
    {
      return $this->price;
    }
    function display()
    {
      printf("<p>%s is a %s, and costs \$%.2f.</p>\n", 
              $this->name, $this->breed, $this->price);
    }
  }
  
  $magpie = new Bird("Malaysia", "magpie", 7.5);
  $magpie->display();
  
  $magpie->setPrice(-14.95);
  $magpie->display();
  
  $magpie->price = -14.95;
  
  $magpie->display();
?>

A Class with a Method

 
<?php
class Item {
  var $name = "item";
  function getName() {
    return "item";
  }
 }
 $item = new Item ();
 print $item->getName ();
?>

Call class methods directly

<?php
   class Visitors
   {
      public function greetVisitor()
      {
         echo "Hello<br />";
      }
      function sayGoodbye()
      {
         echo "Goodbye<br />";
      }
   }
   Visitors::greetVisitor();
   $visitor = new Visitors();
   $visitor->sayGoodbye();
?>

Calling an Overridden Method (PHP 5 Syntax)

 
<?php
 class Item {
   private $name;
   function __construct( $name="item", $code=0 ) {
     $this->name = $name;
     $this->code = $code;
   }
  function getName() {
    return $this->name;
  }
}
class PriceItem extends Item {
  function getName() {
    return "(price) ".parent::getName ();
  }
}
$item = new PriceItem ("widget", 5442);
print $item->getName();
?>

Class Member and Method Definitions

 
Name          Description 
Const         Defines a constant member. 
Public        Accessible from any object of the class. 
Protected     Accessible from the class where it is defined and from inherited classes. 
Private       Accessible from the class where it is defined. 
Static        Modifier. When used alone, public is assumed. 
<?php 
class myclass { 
    public $a; 
    function set_value($val) { 
        $this->a = $val; 
    } 
} 
$obj = new myclass; 
$obj->set_value(123); 
echo "Member a = $obj->a\n"; 
$obj->a = 7; 
echo "Member a = $obj->a\n"; 
?>

Class Member Overloading

 
<?php
     class ParentClass {
          public function callMe() {
               echo "Parent called!\n";
          }
     }
     class ChildClass extends ParentClass {
          public function callMe() {
               echo "Child called!\n";
          }
     }
     $child = new ChildClass;
     $child->callMe();
?>

Defining three member functions for Cat

 
<?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...*";
  }
}
?>

Overriding Methods

 
<?
    class Dog {
            public function bark( ) {
                    print "Woof!\n";
            }
    }
    class Poodle extends Dog {
            public function bark( ) {
                    print "Yip!\n";
            }
    }
?>

Pass class instance as parameter

<?php
    class Employee {
        public $title;
        public $lastName;
        public $firstName;
        public $price;
        
        function __construct( $title, $firstName, $mainName, $price ) { 
            $this->title     = $title;
            $this->firstName = $firstName;
            $this->lastName  = $mainName;
            $this->price     = $price;
        }
        function getFullName() {
            return "{$this->firstName}" . " {$this->lastName}";
        }
    }
    
class EmployeeWriter {
    public function write( $shopProduct ) {
        $str  = "{$shopProduct->title}: ";   
        $str .= $shopProduct->getFullName();
        $str .= " ({$shopProduct->price})\n";
        print $str;
    }
}
$product1 = new Employee( "Title", "A", "B", 5.9 );
$writer = new EmployeeWriter();
$writer->write( $product1 );
?>

The Method of a Child Class Overriding That of Its Parent (PHP 4 Syntax)

 
<?php
 class Item {
   var $name;
   function Item( $name="item", $code=0) {
     $this->name = $name;
     $this->code = $code;
   }
  function getName() {
    return $this->name;
  }
 }
 class PriceItem extends Item {
   function getName() {
     return "(price).".$this->name;
   }
 }
 $item = new PriceItem( "widget", 5442 );
 print $item->getName();
 ?>