PHP: get_class

Description

string get_class ( object obj )

This function returns the name of the class of which the object obj is an instance. Returns FALSE if obj is not an object.

Note: A class defined in a PHP extension is returned in its original notation. In PHP 4 get_class() returns a user defined class name in lowercase, but in PHP 5 it will return the class name in it's original notation too, just like class names from PHP extensions.

Example 1. Using get_class()

<?php class foo { function foo() { // implements some logic } function name() { echo "My name is " , get_class($this) , "\n"; } } // create an object $bar = new foo(); // external call echo "Its name is " , get_class($bar) , "\n"; // internal call $bar->name(); ?>
The above example will output:
Its name is foo My name is foo

User Contributed Notes
get_class

MagicalTux at FF.ST
02-Feb-2004 06:11


Note that the constant __CLASS__ is different from get_class($this) :

<?

  class test {

    function whoami() {

      echo "Hello, I'm whoami 1 !\r\n";

      echo "Value of __CLASS__ : ".__CLASS__."\r\n";

      echo "Value of get_class() : ".get_class($this)."\r\n\r\n";

    }

  }

  class test2 extends test {

    function whoami2() {

      echo "Hello, I'm whoami 2 !\r\n";

      echo "Value of __CLASS__ : ".__CLASS__."\r\n";

      echo "Value of get_class() : ".get_class($this)."\r\n\r\n";

      parent::whoami(); // call parent whoami() function

    }

  }

  $test=new test;

  $test->whoami();

  $test2=new test2;

  $test2->whoami();

  $test2->whoami2();

?>



The output is :

Hello, I'm whoami 1 !

Value of __CLASS__ : test

Value of get_class() : test



Hello, I'm whoami 1 !

Value of __CLASS__ : test

Value of get_class() : test2



Hello, I'm whoami 2 !

Value of __CLASS__ : test2

Value of get_class() : test2



Hello, I'm whoami 1 !

Value of __CLASS__ : test

Value of get_class() : test2



In fact, __CLASS__ returns the name of the class the function is in and get_class($this) returns the name of the class which was created.

Dan
30-Jan-2003 12:00


This function does return the class name in lowercase, but that does not seem to make any difference. The code below, although very sloppy, works fine in all of the following configurations.



PHP 4.2.2 on Windows NT5 with Apache 1.3.24

PHP 4.2.1 in Zend Development Environment on box above

PHP 4.2.3 on Linux RedHat 7.3 with Apache 1.3.27



class TeSt {

   var $a;

   var $b = "Fred";



   // Notice the case difference in the constructor name



   function Test() {

      $classname = get_class($this); // $classname = "test"

      $this->ra = get_class_vars($classname);

   }

}

// Next line also works with Test(), TEST(), or test()

$obj = new TeSt();

print_r($obj->ra);



Result :

   Array

   (

       [a] => 

       [b] => Fred

   )

oliver DOT pliquett @mediagear DOT de
13-Aug-2002 10:07


This function can become _VERY_ helpful if you want to return a new object of the same type. See this example:



<?php

class Foo{

    var $name;

    

    function Foo( $parameter ){

        $this->name = $parameter;

    }



    function whoami() {

        echo "I'm a " . get_class( $this ) ."\n";

    }

    

    function getNew() {

        $className = get_class( $this );

        

        // here it happens:

        return new $className ( "world" ) ;

    }

}

class Bar extends Foo {



    function Bar( $name ){

        $this->Foo( $name );

    }



    function welcome() {

        echo "Hello, " . $this->name .  "! \n";

    } 

}



// We generate a Bar object:

$myBar = new Bar( "Oliver" );

$myBar->welcome();



//now let's instanciate a new Bar object. 

//note: this method is inherited from Foo by Bar!



$baba = $myBar->getNew();



$baba->welcome();

$baba->whoami();



/* Output: 

Hello, Oliver!

Hello, world!

I'm a bar 

*/

?>

philip at cornado dot com
20-Jun-2002 02:15


As of PHP 4.3.0 the constant __CLASS__ exists and contains the class name.

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