If we want to reuse the same set of statements more than once in a program, we need to include them in a macro. For example, a macro can be useful for long calculations or for writing complex WRITE statements. We can only use a macro within a program in which it is defined. Macro definition should occur before the macro is used in the program.
Macros are designed based on placeholders. Placeholder works like pointers in C language. You can define a macro within the DEFINE...END-OF-DEFINITION statement.
Following is the basic syntax of a macro definition:
DEFINE <macro_name>.
<statements>
END-OF-DEFINITION.
......
<macro_name> [<param1> <param2>....].
It is necessary to define a macro first before invoking it. The <param1>…. replaces the placeholders &1...in the ABAP statements contained in the macro definition.
The maximum number of placeholders in a macro definition is nine. That is, when a program is executed, the SAP system replaces the macro by appropriate statements and the placeholders &1, &2,….&9 are replaced by the parameters param1, param2,....param9. We may invoke a macro within another macro, but not the same macro.
Example
Go to transaction SE38. Create a new program ZMACRO_TEST along with the description in the short text field, and also with appropriate attributes such as Type and Status as shown in the following screenshot:
Following is the code:
REPORT ZMACRO_TEST.
DEFINE mac_test.
WRITE: 'This is Macro &1'.
END-OF-DEFINITION.
PARAMETERS: s1 type C as checkbox.
PARAMETERS: s2 type C as checkbox.
PARAMETERS: s3 type C as checkbox default 'X'.
START-OF-SELECTION.
IF s1 = 'X'.
mac_test 1.
ENDIF.
IF s2 = 'X'.
mac_test 2.
ENDIF.
IF s3 = 'X'.
mac_test 3.
ENDIF.
We have 3 checkboxes. While executing the program, let’s select the S2 checkbox.
The above code produces the following output:
A Macro Program
This is Macro 2
If all checkboxes are selected, the code produces the following output:
A Macro Program
This is Macro 1 This is Macro 2 This is Macro 3
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