create simple ABAP class into abap program

The simple ABAP program writes to screen from simple ABAP class method:


program ztest_class.

*--------------------------------------------------------------------
*  www.developerpages.gr
*--------------------------------------------------------------------

class myfirstclass DEFINITION FINAL.
  PUBLIC SECTION.
    methods hello_world.
ENDCLASS.

CLASS myfirstclass implementation.
  METHOD hello_world.
    write :/ 'Hello world from simple ABAP class !'.
  ENDMETHOD.

ENDCLASS.


data : my_hello TYPE REF TO myfirstclass.

START-OF-SELECTION.

* create object
CREATE OBJECT my_hello.

* Call method hello_world
CALL METHOD my_hello->hello_world.

original artticle : http://developerpages.gr/index.php/desktop-development-2/abap/100-create-simple-abap-class-into-abap-program