类的构造方法

*----------------------------------------------------------------------*
*       CLASS calldef DEFINITION
*----------------------------------------------------------------------*
*
*----------------------------------------------------------------------*
CLASS calldef DEFINITION.
  PUBLIC SECTION.
    METHODS constructor."定义构造方法
  PRIVATE SECTION.
    DATA outpara TYPE string.
ENDCLASS.                    "calldef DEFINITION

*----------------------------------------------------------------------*
*       CLASS calldef IMPLEMENTATION
*----------------------------------------------------------------------*
*
*----------------------------------------------------------------------*
CLASS calldef IMPLEMENTATION.
  METHOD constructor."定义执行构造方法
    outpara = 'Execute SAP Construct'.
    WRITE: outpara.
  ENDMETHOD.                    "constructor
ENDCLASS.                    "calldef IMPLEMENTATION

DATA:calldef TYPE REF TO calldef.

START-OF-SELECTION.
  CREATE OBJECT calldef. "初始化类实例对象时即调用构造函数