Form......Endform

[Former Member]

Hi in subroutine Form how 'changing, varying,using' used to pass parameters?Give simple example to understand.

[Former Member]

hi

check this perform

PERFORM f_report_display TABLES t_ekko

t_ekpo

t_fieldcat

• t_events

• t_alv_sort

USING x_print.

FORM f_report_display TABLES p_t_header LIKE t_ekko

p_t_item LIKE t_ekpo

p_t_fieldcat LIKE t_fieldcat

USING p_x_print TYPE slis_print_alv.

DATA: l_repid TYPE sy-repid.

l_repid = sy-repid.

t_keyinfo-header01 = 'EBELN'.

t_keyinfo-item01 = 'EBELN'.

CALL FUNCTION 'REUSE_ALV_HIERSEQ_LIST_DISPLAY'

EXPORTING

i_callback_program = l_repid

i_callback_user_command = c_user_command

it_fieldcat = p_t_fieldcat[]

i_default = 'X'

i_tabname_header = 'T_EKKO'

i_tabname_item = 'T_EKPO'

is_keyinfo = t_keyinfo

is_print = p_x_print

TABLES

t_outtab_header = p_t_header[]

t_outtab_item = p_t_item[].

IF sy-subrc <> 0.

• MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO

• WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.

ENDIF.

regars

kk.

[amit_khare]

Refer the thread -

Regards,

Amit

Reward all helpful replies.

[paruchuri_nagesh]

hi

call by reference

REPORT ZSUBREFERENCE.

data : num1 type i value 5,

num2 type i value 4,

sum type i.

perform addition using num1 num2 .

sum = num1 + num2.

write : sum.

&----

---

*& Form addition

&----

---

• text

----

---

• -->P_NUM1 text

• -->P_NUM2 text

• <--P_SUM text

----

---

form addition using p_num1

p_num2.

p_num1 = 8.

p_num2 = 9.

sum = p_num1 + p_num2.

write sum.

endform. " addition

call by value

REPORT ZSUBREFERENCE.

data : num1 type i value 5,

num2 type i value 4,

sum type i.

perform addition using num1 num2 .

sum = num1 + num2.

write : sum.

&----

---

*& Form addition

&----

---

• text

----

---

• -->P_NUM1 text

• -->P_NUM2 text

• <--P_SUM text

----

---

form addition using value(p_num1)

value( p_num2).

p_num1 = 8.

p_num2 = 9.

sum = p_num1 + p_num2.

write sum.

endform. " addition

Reward for use ful points

Regards

Nagesh.Paruchuri

[Former Member]

Hi,

go thru this.

Defining Subroutines

A subroutine is block of code introduced by FORM and concluded by ENDFORM. Following syntax is used to define a form or subroutine:

FORM <name> <parameters>

. . …..

…

ENDFORM.

Here parameters is optional. You can have plain subroutine without the parameters for example.

FORM SUB1.

… . .

… .

ENDFORM.

Calling Subroutines

You can call subroutines from program by following statement:

PERFORM <subr> [<para>].

Parameters are optional. i.e., you can call subroutine without passing any parameter

Perform SUB1.

Passing Data to Subroutines

When you work with global data in subroutines, you can put a copy of the global data on a local data stack and use it to avoid accidental loss of data (In this way you protect global data.)

You can pass data between calling program and subroutines by using parameters.

• Parameters, which are defined during definition of a subroutine with FORM statement are called ‘formal parameter’.

• Parameters which are specified during the call of a subroutine with the PERFORM statement are called ‘actual parameter’.

Parameters are passed to the FORM either:

• By value

• By Reference

• By value and return.

By Value

Data : a type I value 20.

Perform sub1 using a.

Write a.

FORM sub1 using value (p_a)

P – a = 15

ENDORM.

In this case during subroutine call, the formal parameter are created as copies of actual parameter.

The formal parameters have the memory of their own. Changes made to formal parameter have no effect on the actual parameter.

Like in this case, though value of p_a is changed to 15, it has no effect on ‘a’ which remains as 20.

By Reference

Data: a type I value 20.

Perform sub1 using a.

Write a.

FORM sub1 using value (p_a)

P – a = 15.

ENDORM.

By default system calls all the forms by reference.

In this case, only the address of the actual parameter is transferred to the formal parameters. The formal parameter has no memory of its own. If you change the formal parameter, change is visible in actual parameter also.

By Value and Return

<b>Data : a type I value 20.

Perform sub1 changing a.

FORM sub1 changing value (p_a)

P – a = 15.</b> ENDORM.

In this case if you change formal parameter, then the value of actual parameter is changed when the control is transferred back to the main program.

Assuming A is declared by DATA statement and has value 20 and subroutine SUB1 is called by passing A.

Regards

Srinu

[Former Member]

what is the difference betwn 'by reference' and 'by value and result' ?