Classes that implement the interface IF_OO_ADT_CLASSRUN can be executed directly in Eclipse. The method if_oo_adt_classrun~main is called.
The importing parameter OUT has a method WRITE that can be used to output character strings to the console.

Signature of the WRITE method

write  
 importing data  type any  
           name  type string optional  
 returning value(output)  type ref to if_oo_adt_classrun_out  

CLASS zbc_string_functions DEFINITION
  PUBLIC
  
FINAL
  CREATE PUBLIC .
PUBLIC SECTION.
INTERFACES if_oo_adt_classrun.
ENDCLASS.
CLASS zbc_string_functions IMPLEMENTATION.
METHOD if_oo_adt_classrun~main.
out->write( ‘Hello World’ ).
ENDMETHOD.
ENDCLASS.