ABAP_to_the_Future

2
New Language Features in ABAP 7.4
AND zt_monster_pets~type LIKE 'GIGANTIC%'
AND zt_monster_pets~species IN ('SHARK','CROCODILE','DINOSAUR')
Listing 2.9 Joining Two Tables in Ways Not Possible Before
If you want a table of all the pets of va rious monsters along with some details
about the owning monsters, but you’re only interested in gigantic dinosaurs and
the like, then the query shown in Listing 2.9 is the one for you.
2.2 Declaring and Creating Variables
One of the main differences between ABAP and other languages is that in ABAP
we have been taught to declare all our variables at the start of the program—for
example, in a TOP INCLUDE . Other languages declare them just before they are
used, and such variables tend to be more local in scope—for example, within a
loop. Despite the official ABAP progra mming guidelines, many ABAP programmers
have taken to declaring variables just before they are used for the first time,
for purposes of making the program more readable by humans and hence easier
to change.
The good news is that as time goes on, changes in the ABAP language make this
unofficial practice more and more acceptable. This section will discuss several features
that contribute to this shift.
2.2.1 Omitting the Declaration of TYPE POOL Statements
7.02 Feature
This feature came about with ABAP 7.02, but is discussed here because it’s little known.
Many programs use the ever-popular ABAP_TRUE and ABAP_FALSE constants, and
even more use the built-in icon consta nts to make ALV reports more visually
appealing to users. This us ed to involve declaring a TYPE POOL statement in the
TOP INCLUDE, or at the start of a program, or in the forward declaration property
of the global class. An example of this is shown in Listing 2.10.
TYPE-POOLS: abap,
icon.
Listing 2.10 Declaring a TYPE POOL
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