abap 面向对象学习1

dew

REPORT  Z_OO_01.

class simpleobj definition.             " 类定义
  public section.                           "public like java
   methods show_text.
  private section.                         "private  like java
   data text(40) TYPE c VALUE 'this is my first oo'.
ENDCLASS.

class simpleobj implementation.  " 类的实现
  method show_text.
    WRITE text.
  endmethod.
ENDCLASS.

data ob_app type ref to simpleobj.  "定义类的实例变量

start-of-selection.
create object ob_app.                    " 创建实例对象，like  new Object()
call method ob_app->show_text.   " 类实例调用方法

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

REPORT  Z_OO_02.

class vehicle definition.
  PUBLIC SECTION.
   class-data class_name(10) VALUE 'Vehicle'.
   methods : accelerate,show_speed.
  PROTECTED SECTION.
   data speed TYPE i.
   constants : pi TYPE p decimals 2 VALUE '3.14'.
ENDCLASS.

class vehicle IMPLEMENTATION.
  METHOD accelerate.
    speed = speed + 1.
  ENDMETHOD.
  method show_speed.
    WRITE :/ 'Speed:',speed.
  ENDMETHOD.
ENDCLASS.

data ob_app1 TYPE REF TO vehicle.
data ob_app2 TYPE REF TO vehicle.
data ob_app3 TYPE REF TO vehicle.
data o_vehicle TYPE REF TO vehicle.

start-of-selection.
create OBJECT : ob_app1,
                 ob_app2.

WRITE : 'ob_app1',ob_app1->class_name.
WRITE :/ 'ob_app2',ob_app1->class_name.
WRITE :/ 'vehicle',vehicle=>class_name.

skip.

vehicle=>class_name = 'Ship'.
WRITE : 'ob_app1',ob_app1->class_name.
WRITE :/ 'ob_app2',ob_app1->class_name.
WRITE :/ 'vehicle',vehicle=>class_name.

  skip.

vehicle=>class_name = 'Bus'.
create object ob_app3.
WRITE :/ 'ob_app3',ob_app3->class_name.

call method ob_app3->accelerate.
call method ob_app3->show_speed.

create OBJECT o_vehicle.

DO 5 TIMES.
  call METHOD o_vehicle->accelerate.
ENDDO.
  call METHOD o_vehicle->show_speed.

data o_vehicle2 LIKE o_vehicle.

o_vehicle2 = o_vehicle.

clear o_vehicle.
if o_vehicle is not INITIAL.
call METHOD o_vehicle->show_speed.
endif.
call METHOD o_vehicle2->show_speed.
WRITE '对象只要有被引用的变量，就是活动的'.

zwnowok

感谢分享