Give an object a valid starting state
A tracker without a tracking code is not useful. An instance constructor runs when an object is created and can receive the values needed to establish that object’s initial state.
Instance constructor
CLASS lcl_tracker DEFINITION.
PUBLIC SECTION.
DATA tracking_code TYPE string.
METHODS constructor IMPORTING iv_tracking_code TYPE string.
ENDCLASS.
CLASS lcl_tracker IMPLEMENTATION.
METHOD constructor.
tracking_code = iv_tracking_code.
ENDMETHOD.
ENDCLASS.
DATA(tracker) = NEW lcl_tracker( iv_tracking_code = 'PK-204' ).In a real class, keep the attribute private and validate the input before storing it. The constructor should make it difficult to create an object in a state that later methods cannot handle.
Class constructor is different
CLASS_CONSTRUCTOR is called automatically before the class is first accessed in the relevant internal session. It has no importing parameters and should not be used as a general setup hook for every object. Avoid putting business workflows, user-specific state, or unpredictable external work there.
Choosing initialization alternatives
Use the instance constructor for required object-specific dependencies or values. Use ordinary factory methods when creation needs named choices, validation results, or a more expressive API. Avoid a public attribute that callers must remember to populate after construction.
Practice
Add a constructor importing iv_tracking_code, store it, instantiate the class with PK-204, and set result from the created object. Add the selected mode’s output. This checker does not activate or run ABAP.
Version note: Constructor syntax and API restrictions depend on the target ABAP language version.
Sources
- SAP Samples, ABAP Object Orientation: constructors
- SAP Help Portal, ABAP Objects overview
Developer practice · ABAP
Practice: validate a parcel at creation
Define a constructor that receives a tracking code and stores it in the object, then create a tracker and copy its code to result.
This choice changes the output pattern checked here: WRITE belongs in a classic executable report, while out->write( ) uses the supplied output reference in an ABAP Cloud class-run method. It does not switch the language version of the other code; check release and API availability in your target system.
Complete the task and include the output statement shown for your selected environment. Variable names can differ if you use them consistently. This browser checker checks structure only; it does not compile or run ABAP.
0 required structures detected · 0 checks
Write your solution, then check its structure.
One possible solution
CLASS lcl_tracker DEFINITION.
PUBLIC SECTION.
DATA tracking_code TYPE string.
METHODS constructor IMPORTING iv_tracking_code TYPE string.
ENDCLASS.
CLASS lcl_tracker IMPLEMENTATION.
METHOD constructor.
tracking_code = iv_tracking_code.
ENDMETHOD.
ENDCLASS.
DATA(tracker) = NEW lcl_tracker( iv_tracking_code = 'PK-204' ).
DATA(result) = tracker->tracking_code.
WRITE result.out->write( result ).These are context-specific output examples. In your own program, use the result variable from your solution and the output mechanism available in that program.