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Give it a state

Attributes declaration

Using your local class, let's declare the following attributes :

company		| instance attribute  | public  | string
plane_number    | instance attribute  | public  | string
nb_seats 	| static attribute    | public  | number
nb_passengers	| instance attribute  | public	| number
manufacturer	| constant| public    | string  | 'Airbus'
nb_of_flight     | ?    		| ? 	  | ?
on_ground        | ?    		| ? 	  | ?
serial_number    | instance attribute   | private | string
cockpit_firmware | static attribute   	| private | string
manufacturer_key | constant	      	| private | string  | 'AIB_FAL350'
random_gen	 | static attribue	| private | cl_abap_random_int

*Tips Instance attributes are declare using keyword DATA Static attributes are declare using keyword ClASS-DATA Constant attributes are declare using keyword CONSTANTS

CLASS lcl_flight DEFINITION.

  PUBLIC SECTION.
    CONSTANTS: c_manufacturer type string value 'Airbus'.
    DATA : mv_plane_number type string,
    	   mv_nb_seats type i,
	   mv_nb_passengers type i.
    CLASS-DATA: mv_nb_of_planes type i.
  PRIVATE SECTION.

ENDCLASS

Repeat process to complete the class definition with the private attributes defined at the beginning of this exercise.

Now, your class should look like this:

CLASS lcl_flight DEFINITION.

  PUBLIC SECTION.
  
    CONSTANTS: c_manufacturer TYPE string VALUE 'Airbus'.
    CLASS-DATA: mv_nb_of_planes TYPE i.
    DATA : mv_plane_number  TYPE string,
           mv_nb_seats      TYPE i,
           mv_nb_passengers TYPE i,
           mb_on_ground     TYPE abap_bool,
           mv_company       TYPE string.
	   
  PRIVATE SECTION.
    CONSTANTS: c_manufacturer_key TYPE string VALUE 'AIB_FAL350'.
    DATA : mv_serial_number TYPE string.
    CLASS-DATA: mv_cockpit_firmware TYPE string,
                mo_random_gen       TYPE REF TO cl_abap_random_int,
                mv_nb_flights       TYPE i.
ENDCLASS.

Give it a behavior

Still using your local class, let's declare the following behaviors :

  • class_constructor
CLASS lcl_flight DEFINITION.
	PUBLIC SECTION.
	[...]
	CLASS-METHODS : class_constructor.
ENDCLASS.

CLASS lcl_flight IMPLEMENTATION.
	METHOD 	class_constructor.
      
		DATA: n type i,
		     seed type i.

		seed = cl_abap_random=>seed( ).

		cl_abap_random_int=>create(
		  exporting
		    seed = seed
		    min = 0
		    max = 10000
		  receiving
		    prng = mo_random_gen
		).
	ENDMETHOD.
ENDCLASS.
  • constructor
CLASS lcl_flight DEFINITION.
	PUBLIC SECTION.
	[...]
	constructor IMPORTING iv_plane_number TYPE i
			      iv_company TYPE string.
ENDCLASS.

CLASS lcl_flight IMPLEMENTATION.
	METHOD 	constructor.
	mv_plane_number = iv_plane_number.
	mv_company  =  iv_company.
	mv_nb_seats = 250.
	mv_serial_number = mo_random_gen->get_next( ).
	ENDMETHOD.
ENDCLASS.
  • get_free_seats | instance method | public
CLASS lcl_flight DEFINITION.
	[...]
	METHODS: get_free_seats RETURNING VALUE(rv_nb_seats) TYPE i.
ENDCLASS.
CLASS lcl_flight IMPLEMENTATION.
	METHOD get_free_seats.
		rv_nb_seats = mv_nb_seats - mv_nb_passengers..
	ENDMETHOD.
ENDCLASS.
  • add_flight | static method | public
CLASS lcl_flight DEFINITION.
	[...]
	CLASS-METHODS: add_flight IMPORTING  	iv_plane_number TYPE i
 						iv_company TYPE string
				  RETURNING VALUE(ro_flight) TYPE REF TO lcl_flight.
ENDCLASS.
CLASS lcl_flight IMPLEMENTATION.
	METHOD add_flight.
		ro_flight = NEW lcl_flight( iv_plane_number = iv_plane_number
					    iv_company = iv_company ).
		ADD 1 to mv_nb_flights.
	ENDMETHOD.
ENDCLASS.
  • add_passengers | instance method | public
CLASS lcl_flight DEFINITION.
	[...]
	METHODS: add_passengers IMPORTING iv_passengers TYPE i.
ENDCLASS.
CLASS lcl_flight IMPLEMENTATION.
	METHOD add_passengers.
		ADD  iv_passengers TO mv_nb_passengers.
	ENDMETHOD.
ENDCLASS.
  • declare_take_off | instance method | private
CLASS lcl_flight DEFINITION.
	[...]
	METHODS: declare_take_off.
ENDCLASS.
CLASS lcl_flight IMPLEMENTATION.
	METHOD declare_take_off.
		WRITE: 'Flight' && mv_serial_number && 'taking off'.
	ENDMETHOD.
ENDCLASS.
  • take_off | instance method | public
CLASS lcl_flight DEFINITION.
	[...]
	METHODS: take_off.
ENDCLASS.
CLASS lcl_flight IMPLEMENTATION.
	METHOD take_off.
		mb_on_ground = abap_false.
		me->declare_take_off( ).
		"OR
		declare_take_off( ).
		"OR
		CALL METHOD declare_take_off( ).
	ENDMETHOD.
ENDCLASS.
  • get_nb_flights | static method | public
CLASS lcl_flight DEFINITION.
	[...]
	CLASS-METHODS: get_nb_flights RETURNING VALUE(rv_nb_flights) TYPE i.
ENDCLASS.
CLASS lcl_flight IMPLEMENTATION.
	METHOD get_nb_flights.
		rv_nb_flights = mv_nb_flights.
	ENDMETHOD.
ENDCLASS.

Now in the report, after class definition and implementation, let's add this :

↑↑↑↑
"class definition & implementation above

END-OF-SELECTION.

DATA : lo_flight TYPE REF TO lcl_flight.

CREATE OBJECT lo_flight 
	EXPORTING iv_plane_number = '354'
		  iv_company	  = 'SIA'.
		  
lo_flight->add_passengers( 10 ).
lo_flight->take_off( ).

DATA(lo_flight2) = lcl_flight=>add_flight( 
			iv_plane_number = '9443'
			iv_company	  = 'AFR').
			
lo_flight->add_passengers( 56 ).
lcl_flight=>get_nb_flights( ).
WRITE:/ lcl_flight=>get_nb_flights( ).

💡 Compile (CTRL + F3).

Run the report (F8)

  • What is the current state of mb_on_ground of lo_flight ? of lo_flight2 ?

  • What is the output of this statement lcl_flight=>get_nb_flights( ) ?