Declaring Local Class in ABAP Report

In this tutorial we will learn about how to declare local class and use it in a report program.

KEY POINTS:

• The first step is to give a class definition.
• Next implement the class and its methods.
• Declare a reference to the class.
• Create an object of the class and use it to call the methods of the class.

EXAMPLE:

REPORT  zlocal_class.

*--Class Definition

CLASS l_test DEFINITION.

   PUBLIC SECTION.

*--data declaration

     DATA: info TYPE string.

*--methods

     METHODS:

     constructor     IMPORTING p_balance TYPE dmbtr,

     set_balance    IMPORTNG  p_set TYPE dmbtr,

                           EXPORTING p_amount TYPE dmbtr,

     display.

  PRIVATE SECTION.

    DATA : balance TYPE dmbtr.

ENDCLASS.      " end of class definition

*--Class Implementation

 CLASS l_test IMPLEMENTATION.

    METHOD constructor.

      WRITE: / 'inside constructor'.

       balance  = p_balance.

      WRITE: /  'value'  ,  balance.

    ENDMETHOD.

    METHOD set_balance.

       balance = p_set.

    ENDMETHOD.

   METHOD display.

      WRITE : / ' set the balance'.

      WRITE :  balance.

   ENDMETHOD.

ENDCLASS.

*--Report 

*-- Declare the reference.

 DATA:  test TYPE REF TO  l_test.

*declare a parameter on selection screen.

PARAMETERS: p_val TYPE dmbtr.

START-OF-SELECTION.

*--create object

CREATE OBJECT test 

    EXPORTING 

     p_balance =  40.                          <-- This will be passed to the constructor.

*-- call method set_balance.

CALL METHOD test->set_balance  <-- call the method to set balance.

    EXPORTING

      p_set = p_val.

*-- call method display.

CALL METHOD test->display.        <-- call method display.

  ----------------------------------------------------------------------------------------------------------

INPUT :

 P_VAL  = 500.

OUTPUT:

inside constructor

value 40

set the balance 500

-----------------------------------------------------------------------------------------------------------

Notes :  

• The method constructor is called when the object is created using CREATE OBJECT statement.
• The method set_balance s used to set the value or assign the value of parameter to the class attribute balance.
• The attribute 'balance' is private and hence can only be accessed through class methods.
• The method display will print the value of balance attribute.