How to use macro's functionality in a programe...?

Question

hi,
i am siva,
i am new to abap,
i am not having clarity on how to use macro in a programe,
please send me any source code of a programe which
contain functionality of macros..?
and explain functionality of macros...?
i any of u know answer..
please send me source code of a programe that use macros...?
reguars,
siva.

Answer 1

Hi,
<u>Macros:</u>
If you want to reuse the same set of statements more than once in a program, you can include
them in a macro. For example, this can be useful for long calculations or complex WRITE
statements. You can only use a macro within the program in which it is defined, and it can only
be called in lines of the program following its definition.
The following statement block defines a macro <macro>:
DEFINE <macro>.
<statements>
END-OF-DEFINITION.
You must specify complete statements between DEFINE and END-OF-DEFINITION. These
statements can contain up to nine placeholders (&1, &2, ..., &9). You must define the macro
before the point in the program at which you want to use it.
Macros do not belong to the definition part of the program. This means that the DEFINE...ENDOF-
DEFINITION block is not interpreted before the processing blocks in the program. At the
same time, however, macros are not operational statements that are executed within a
processing block at runtime. When the program is generated, macro definitions are not taken
into account at the point at which they are defined. For this reason, they do not appear in the
overview of the structure of ABAP programs [Page 44].
A macro definition inserts a form of shortcut at any point in a program and can be used at any
subsequent point in the program. As the programmer, you must ensure that the macro
definition occurs in the program before the macro itself is used. Particular care is required if you
use both macros and include programs, since not all include programs are included in the syntax
check (exception: TOP include).
To use a macro, use the following form:
<macro> [<p1> <p2> ... <p9>].
When the program is generated, the system replaces <macro> by the defined statements and
each placeholder &i by the parameter <pi>. You can use macros within macros. However, a
macro cannot call itself.
Ex:
DATA: RESULT TYPE I,
N1 TYPE I VALUE 5,
N2 TYPE I VALUE 6.
DEFINE OPERATION.
RESULT = &1 &2 &3.
OUTPUT &1 &2 &3 RESULT.
END-OF-DEFINITION.
DEFINE OUTPUT.
WRITE: / 'The result of &1 &2 &3 is', &4.
END-OF-DEFINITION.
OPERATION 4 + 3.
OPERATION 2 ** 7.
OPERATION N2 - N1.
The produces the following output:
The result of 4 + 3 is 7
The result of 2 ** 7 is 128
The result of N2 - N1 is 1
Here, two macros, OPERATION and OUTPUT, are defined. OUTPUT is nested in
OPERATION. OPERATION is called three times with different parameters. Note how
the placeholders &1, &2, ... are replaced in the macros.
Regards,
Bhaskar