Sunday, 30 April 2017

Bitwise operation ( OR, AND, XOR ) on ABAP Integer

For training purpose I need to explain to my ABAP team colleagues about how bitwise operation on Integer in Java like below is done.

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And since the bitwise operation in ABAP can only support data type X and XSTRING,

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so now I create a prototype which can support bitwise operation OR, AND, XOR on int4 in ABAP for teaching purpose.

Still remember the wrapper class Integer in Java which is explained in my blog Integer in ABAP, Java and JavaScript?

I just create a wrapper class ZCL_INTEGER in ABAP by following the design idea used in Java.

Usage of ZCL_INTEGER


Here below the usage of this wrapper class is explained.

Get instance of ZCL_INTEGER

In Java you use the following code to get an instance of wrapper class Integer:

Integer a = Integer.valueOf(1);

In ABAP:

data(int1) = zcl_integer=>value_of( 3 ).
data(inta) = zcl_integer=>value_of( 3 ).
data(int2) = zcl_integer=>value_of( 2 ).

ASSERT int1 = inta.

The same primitive int value will always lead to exactly the same instance of ZCL_INTEGER. I achieve this by using an internal table MT_CACHE in ZCL_INTEGER as a cache.

Get integer’s binary representation


A string for the integer’s binary format is returned by simply calling method get_binary_format.

data(int1) = zcl_integer=>value_of( 3 ).
data(int2) = zcl_integer=>value_of( 2 ).
WRITE:/ int1->get_binary_format( ).
WRITE:/ int2->get_binary_format( ).

Result:

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Bitwise operation


Use instance method OR, AND and XOR accordingly.
Test code:

data(int1) = zcl_integer=>value_of( 3 ).
data(int2) = zcl_integer=>value_of( 2 ).

data(int3) = zcl_integer=>value_of( 12 ).
data(int4) = zcl_integer=>value_of( 4 ).

data(int5) = zcl_integer=>value_of( 24 ).
data(int6) = zcl_integer=>value_of( 4 ).

WRITE:/ int1->or( int2 )->get_raw_value( ).
WRITE:/ int3->and( int4 )->get_raw_value( ).
WRITE:/ int5->xor( int6 )->get_raw_value( ).

Same output as Java:

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Now let’s try to do more interesting task: swap the two integer without using intermediate variable 🙂

DATA(a) = zcl_integer=>value_of( 20 ).
DATA(b) = zcl_integer=>value_of( 30 ).

a = a->xor( b ).
b = a->xor( b ).
a = a->xor( b ).

WRITE:/ a->get_raw_value( ).
WRITE:/ b->get_raw_value( ).
Test output, swap is done

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You can get source code of ZCL_INTEGER from my github. Currently this toy only supports unsigned integer.

Please manually create these three simple DDIC objects before you activate the code:

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ZBIT domain

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SAP ABAP Tutorials and Materials, SAP ABAP Certifications, SAP ABAP Guide

Data element for BIT type

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And table type:

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