Data Definition

For first part of  Introduction first and then go on with the below details for a better understanding of concepts.

DATA(ld_erg) = lo_obj->get_data( ).   "The first example calls the get_data method of the object lo_obj,  which returns a result as the returning parameter.

Passing values to constructor

Now we can pass value while creating the object itself check the line highlighted in yellow.

*&---------------------------------------------------------------------*
*& Report y_class_basics
*&---------------------------------------------------------------------*
*&
*&---------------------------------------------------------------------*
report y_class_basics.

class abap_basics definition.

public section.

     data : num type i value '10'.
     methods : display,
             constructor importing lv_value type i.

     private section.
     data value_to_constrictor type  i. "private data can be accessed within the same class

endclass.

class abap_basics implementation.


  method display.
       data : num type i value '200'.
              write : 'value = ', num.
              write : 'value in me = ', me->num.
  endmethod.

  method constructor.
  value_to_constrictor  = lv_value. " lv_value holds value 1
  endmethod.

endclass.

start-of-selection.

DATA(lo_object) = NEW abap_basics( lv_value = '1' ). "passing parameter which is      present in the constructor
lo_object->display( ).

You can convert the data passed to the method to the type that method needs.

DATA(lo_object) = NEW abap_basics( CONV #('1' ) ).

Method Chaining

go_invoice_manager->mt_invoices[ 4 ]-ref->do_payment( ).

Let’s break down the entire chain step by step and look at the individual elements:

• go_invoice_manager – Global reference to an object
• mt_invoices – Public attribute of the reference go_invoice_manager and a table by name
• [ 4 ] – Read the 4th line of the table
• -ref – Access to a field of the 4th line with the name “ref”, which in turn is a reference
• do_payment( ) – Calling the method of the object