CREATE OR REPLACE FUNCTION FCOUTPUT_TEST_LEVEL_2(  
  O_VAR_OUT OUT number)  
RETURN varchar2 IS  
  ---  
  l_var_out number;  
  ---  
BEGIN  
  ---   
  l_var_out := 123456;  
  ---  
  O_VAR_OUT := l_var_out;  
  ---  
  RETURN('S');  
  ---  
EXCEPTION  
WHEN OTHERS THEN  
  ---  
  RAISE;  
  ---  
END FCOUTPUT_TEST_LEVEL_2;  
---  

CREATE OR REPLACE FUNCTION FCOUTPUT_TEST_LEVEL_1(  
  O_VAR_OUT OUT number)  
RETURN varchar2 IS  
  ---  
  l_ret         varchar2(1);  
  l_error_msg   varchar2(3999);  
  l_var_out number;  
  ---  
  E_FUNC_RETURN_NOT_SUCCESS EXCEPTION;  
  C_FUNC_RETURN_NOT_SUCCESS CONSTANT INTEGER := -20003;  
  PRAGMA EXCEPTION_INIT (E_FUNC_RETURN_NOT_SUCCESS, C_FUNC_RETURN_NOT_SUCCESS);  
  ---  
BEGIN  
  ---   
/* 
note: another test that was done was to replace  
"RAISE_APPLICATION_ERROR(C_FUNC_RETURN_NOT_SUCCESS,'FM',NULL);" with "RAISE E_FUNC_RETURN_NOT_SUCCESS",  
if you do this, the output values ​​are returned with the expected values ​​(that is, empty/null) 
*/ 
  dbms_output.put_line('Where = 1');  
  l_ret := FCOUTPUT_TEST_LEVEL_2(O_VAR_OUT => l_var_out);  
  ---  
  IF l_ret != 'S' THEN  
    ---  
  dbms_output.put_line('Where = 1.1');  
    RAISE_APPLICATION_ERROR(C_FUNC_RETURN_NOT_SUCCESS  
                           ,'FM'  
                           ,NULL);  
    ---  
  END IF;  
  ---  
  dbms_output.put_line('Where = 2');  
  l_ret := 'U';  
  ---  
  IF l_ret != 'S' THEN  
    ---  
  dbms_output.put_line('Where = 2.1');  
    RAISE_APPLICATION_ERROR(C_FUNC_RETURN_NOT_SUCCESS  
                           ,'FM'  
                           ,NULL);  
    ---  
  END IF;  
  ---  
  dbms_output.put_line('Where = 3');  
  O_VAR_OUT := l_var_out;  
  ---  
  RETURN('S');  
  ---  
EXCEPTION  
WHEN e_func_return_not_success THEN  
  ---  
  dbms_output.put_line('Where = 9');  
  RETURN(l_ret);  
  ---  
WHEN OTHERS THEN  
  ---  
  RAISE;  
  ---  
END FCOUTPUT_TEST_LEVEL_1;  
---  

DECLARE  
  -- Declarations  
  var_RetVal      VARCHAR2 (32767);  
  var_O_VAR_OUT   NUMBER;  
  
BEGIN  
  -- Call  
  var_RetVal := FCOUTPUT_TEST_LEVEL_1 (O_VAR_OUT => var_O_VAR_OUT);  
  
  -- Outputs  
  dbms_output.PUT_LINE ('RetVal = ' || var_RetVal);  
  dbms_output.PUT_LINE ('O_VAR_OUT = ' || var_O_VAR_OUT);  
  dbms_output.PUT_LINE ('');  
  
END;