actual &formal

[Former Member]

hi all,

what is actual and formal parameters?

what is the use of them in the program?

how to and where to use actural and formal parameters?

pls can i have the sample code which helps in understanding better?

thanks in advance,

jacob.

[Former Member]

Hi,

both actual and formal parameters hold the value of a variable, but the difference lies in the visibility.

The format parameter is visible only in the local block , where it is define(e.g., inside a subroutine), but the actual parameter is visible globaly i.e. in the main prog and in the subroutine.

[Former Member]

Hi ,

When you are working with routines, FM you will come across with actual & formal parameters.

Example.....

PERFOM select_data using lv_date, lv_matnr

here the lv_date and lv_matnr are actual parameters.

when write the Form routine

FORM select_data using p_date type lv_date

p_matnr type lv_matnr

here p_date and p_matnr is formal parameters.

hope your question is answered.

Thanks & Regards

Madhavi

[matt]

>

> Hi,
> both actual and formal parameters hold the value of a variable, but the difference lies in the visibility.
> The format parameter is visible only in the local block , where it is define(e.g., inside a subroutine), but the actual parameter is visible globaly i.e. in the main prog and in the subroutine.

Incorrect or at least, misleading.

If you call form B from form A, the actual parameters may well be local to form A.

[Former Member]

Hi,

Cinsider the following example

DATA: w_val TYPE I.
PERFORM f_increment USING w_val.
***

FORM f_increment USING us_val TYPE I.

us_val = us_val + 1.
ENDFORM.

In the above code, w_val is Actual paramener.

But us_val is the formal parameter,as its only visible inside a particular routine.

Data is copied from actual parameter to formal parameter, when we call a PERFORM,

[narin_nandivada3]

Hi Jacob,

Please refer to this SAP HELP for better understanding..

http://help.sap.com/saphelp_nw04/helpdata/en/9f/db984635c111d1829f0000e829fbfe/content.htm

And also check the Examples specified in the above link

For further help..check this thread...

Hope this would help you and put some light for you regarding this topic.

Good luck

Narin

[Former Member]

hiii

Actual and formal parameters are used in modularization technique.it is used while calling a subroutine.

we use subroutines using PERFORM statement and the functionality of this subroutine is defined using FORM and ENDFORM statements.

Here variables used in perform statement are called ACTUAL PARAMETERS and the variables used in form, endform statements are called FORMAL parameters. when program execution is there, actual parameters are passed to the formal parameters.

EXAMPLE:

data:

wa_num type i.

parameters:

p_num2 type i,

p_num3 type i.

perform multiply using p_num2 p_num3 wa_num. " these are actual parameters.

write:/ p_num3.

form multiply using x y z. " x, y and z are formal parameters.

z = x + y.

endform.

regards

twinkal

[Former Member]

Hi,

Example of Actual Parameters:

PERFORM INCREMENT_VALUE USING previous_val CHANGING new_val.

Here previous_val and new_val are the Actual parameters...

Example of FORMAL Parameters:

FORM INCREMENT_VALUE USING p_prev_val CHANGING p_new_val.

p_new_val = p_prev_val + 1.

ENDFORM.

Here p_prev_val and p_new_val are FORMAL parameters...

Formal parameters have visibility inside the FORM and ENDFORM statements only...

Regards,

Kunjal

[bpawanchand]

HI

DATA :
  w_i TYPE i VALUE 6.

PERFORM display USING  w_i ..   "<<-------Actual Parameter


FORM display  USING  value(p_w_i) TYPE i..
  WRITE :
    / p_w_i.                                 "<<----- Formal Parameter
ENDFORM.                    " display

regards

pavan

[Former Member]

Hi,

The difference is parameters which are vissible inside the Function Module are called Formal Parameters.

The Parameters which are passed to the Function Module are called Actual Parameters.

REPORT Zexample_1 .

DATA: num1 TYPE i,

num2 TYPE i,

sum TYPE i.

num1 = 2. num2 = 4.

PERFORM addit USING num1 num2 CHANGING sum.

num1 = 7. num2 = 11.

PERFORM addit USING num1 num2 CHANGING sum.

FORM addit

USING add_num1 TYPE any

add_num2 TYPE any

CHANGING add_sum TYPE any.

add_sum = add_num1 + add_num2.

PERFORM out USING add_num1 add_num2 add_sum.

ENDFORM.

FORM out

USING out_num1 TYPE any

out_num2 TYPE any

out_sum TYPE any.

WRITE: / 'Sum of', out_num1, 'and', out_num2, 'is', out_sum.

ENDFORM.

Actual and Formal parameters both contain the values.

Here in the present Example.

num1 and num2----

---

> Actual Parameters and add_num1 and add_num2 -

---

> Formal Parameters.

[Former Member]

hi Jacob,

continuing my above post, the sample code is

REPORT  z_test.


PARAMETERS:
     a_var1 TYPE i,
     a_var2 TYPE i.


PERFORM test USING a_var1
                   a_var2.


WRITE:
  / 'In main prog:',
     'Value of var1:',a_var1,
      'Value of var2:',a_var2.
*&---------------------------------------------------------------------*
*&      Form  test
*&---------------------------------------------------------------------*
*       text
*----------------------------------------------------------------------*
*      -->P_A_VAR1  text
*      -->P_A_VAR2  text
*----------------------------------------------------------------------*
FORM test  USING    p_a_var1
                    p_a_var2.

  DATA: f_var1 TYPE i,
        f_var2 TYPE i,
        temp TYPE i.

  f_var1 = p_a_var1.
  f_var2 = p_a_var2.


  temp   = f_var1.
  f_var1 = f_var2.
  f_var2 = temp.

  WRITE:
 / 'In Subroutine:',
    'Value of var1:',f_var1,
    'Value of var2:',f_var2.

it is self explanetory with our old example of SWAPPING . where the value of formal parameters (f_var1 and f_var2) are swapped but the actuals (a_var1 and a_var2)remains same.

Regards,

Anirban