Ask whether a value belongs to one object or the class

Each parcel has its own tracking code. A service label may be shared by every tracker. ABAP’s instance components belong to an object; class components belong to the class itself.

Instance data varies per instance

DATA tracking_code TYPE string.

If this declaration is in the public section, each instance has its own value. In a well-encapsulated class it would usually be private and accessed through methods.

Class data and class methods are shared

CLASS-DATA service_label TYPE string VALUE 'Parcel desk'.
CLASS-METHODS label RETURNING VALUE(result) TYPE string.

Call a static/class method with class_name=>method( ). Class data has one shared value in the relevant class runtime context, not one value per instance. It can be appropriate for immutable metadata or carefully managed shared state.

Static is not automatically better

An instance is usually clearer when data belongs to a parcel, order, or request. Mutable class data introduces hidden coupling: one caller can change what another caller observes, which complicates parallel work and tests. Prefer constants for fixed shared values and dependency injection for collaborators; use mutable static state only when the design requires it.

Practice

Declare instance-level tracking_code, class-level service_label, and a class method that returns the label as result. Add the environment-appropriate output. The checker looks for patterns only.

Classic and Cloud: Core class syntax is broadly shared, but allowed APIs and language versions differ. For Cloud console output, the result must be written from the class-run method’s provided out reference; classic report output uses WRITE.

Sources

• SAP Samples, ABAP Object Orientation: attributes and methods
• SAP Help Portal, ABAP Objects overview

CLASS lcl_tracking DEFINITION.
  PUBLIC SECTION.
    DATA tracking_code TYPE string.
    CLASS-DATA service_label TYPE string VALUE 'Parcel desk'.
    CLASS-METHODS label RETURNING VALUE(result) TYPE string.
ENDCLASS.
CLASS lcl_tracking IMPLEMENTATION.
  METHOD label.
    result = service_label.
  ENDMETHOD.
ENDCLASS.
DATA(result) = lcl_tracking=>label( ).

WRITE result.

out->write( result ).