Implementing constructor outside class implementation..

Question

REPORT  ZTUSH.
CLASS counter DEFINITION.
  PUBLIC SECTION.
    METHODS CONSTRUCTOR.
    CLASS-METHODS: set IMPORTING value(set_value) TYPE i,
             increment,
             get EXPORTING value(get_value) TYPE i.
   PRIVATE SECTION.
   CLASS-DATA count TYPE i.
ENDCLASS.
METHOD CONSTRUCTOR.
WRITE:/ 'I AM CONSTRUCTOR DUDE'.
ENDMETHOD.
CLASS counter IMPLEMENTATION.
METHOD set.
    count = set_value.
  ENDMETHOD.
ENDCLASS.
DATA cnt TYPE REF TO counter.
START-OF-SELECTION.
  CREATE OBJECT cnt.
  CALL METHOD counter=>set EXPORTING set_value = number.
I THOUGHT WE CAN DEFINE CONSTRUCTOR METHOD OUTSIDE CLASS IMPLEMENTATION AS IN JAVA. But when I do that I get an error, method can be implemented only withing class. Why?

Answer 1

Hello Rajesh
I do not fully understand what you mean by "I THOUGHT WE CAN DEFINE CONSTRUCTOR METHOD OUTSIDE CLASS IMPLEMENTATION AS IN JAVA". However, if you mean that we can create an object without having an explicit CONSTRUCTOR method defined then this is possible in ABAP like in Java (see coding below).
Regards
  Uwe
REPORT ztush.
*       CLASS counter DEFINITION
CLASS counter DEFINITION.
  PUBLIC SECTION.
*METHODS CONSTRUCTOR.
    CLASS-METHODS: set IMPORTING value(set_value) TYPE i,
    increment,
    get EXPORTING value(get_value) TYPE i.
  PRIVATE SECTION.
    CLASS-DATA count TYPE i.
* NO explicit constructor
*METHOD CONSTRUCTOR.
*WRITE:/ 'I AM CONSTRUCTOR DUDE'.
*ENDMETHOD.
ENDCLASS.                    "counter DEFINITION
*       CLASS counter IMPLEMENTATION
CLASS counter IMPLEMENTATION.
  METHOD set.
    count = set_value.
  ENDMETHOD.                    "set
  METHOD get.
  ENDMETHOD.                    "get
  METHOD increment.
  ENDMETHOD.                    "increment
ENDCLASS.                    "counter IMPLEMENTATION
DATA cnt TYPE REF TO counter.
START-OF-SELECTION.
* Implicit constructor is called
  CREATE OBJECT cnt.
  CALL METHOD counter=>set
    EXPORTING
      set_value = 5.
END-OF-SELECTION.