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关于abap:ABAP整型类型的几种位操作-OR-AND-XOR

jiezi

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

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

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:

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:

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


Currently this toy only supports unsigned integer.

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

ZBIT domain


Data element for BIT type

And table type:

Further reading

I have written a series of blogs which compare the language feature among ABAP, JavaScript and Java. You can find a list of them below:

  • Lazy Loading, Singleton and Bridge design pattern in JavaScript and in ABAP
  • Functional programming – Simulate Curry in ABAP
  • Functional Programming – Try Reduce in JavaScript and in ABAP
  • Simulate Mockito in ABAP
  • A simulation of Java Spring dependency injection annotation @Inject in ABAP
  • Singleton bypass – ABAP and Java
  • Weak reference in ABAP and Java
  • Fibonacci Sequence in ES5, ES6 and ABAP
  • Java byte code and ABAP Load
  • How to write a correct program rejected by compiler: Exception handling in Java and in ABAP
  • An small example to learn Garbage collection in Java and in ABAP
  • String Template in ABAP, ES6, Angular and React
  • Try to access static private attribute via ABAP RTTI and Java Reflection
  • Local class in ABAP, Java and JavaScript
  • Integer in ABAP, Java and JavaScript
  • Covariance in Java and simulation in ABAP
  • Various Proxy Design Pattern implementation variants in Java and ABAP
  • Tag(Marker) Interface in ABAP and Java
  • Bitwise operation (OR, AND, XOR) on ABAP Integer
  • An interview question: Compare two integers without +,-,*,/ or > and <

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