Skipping a level in the data division

[TedHolt]

I saw something today I've never seen before.

01  aaa.
        03 bbb    pic xx.
    02  ccc.
        03   ddd    pic xxx.
        03   eee    pic xxx.
    02  fff.
        03  ggg     pic x.
        03  hhh     pic x.

I didn't realize the compiler would allow a lower-level (bbb) before a higher one (ccc). Apparently it treats it as if the programmer had coded an 02 filler after aaa. It seems like sloppy programming to me. What do you think?

[tomliotta]

Re: Skipping a level in the data division

It's a potential problem for future maintenance, but it's valid. Levels from 02 through 49 have no intrinsic meaning except when a level number is higher than the immediately preceding level number, thereby making it subordinate. As I understand it, the qualification by names is what's really important; and level numbers guide the resolution of that qualification.

The 03-item is effectively logically at the same level as the 02-items. Perhaps there was a 02-group at one time that included that 03-item, and when it was removed, the 03-item was left by mistake. A future developer might never know the intention whether on purpose or by mistake. If on purpose, a reason comment should explain the point.

IMO, if the indentation is accurate, the best that can be said is that it provides a visual clue.

[TedHolt]

Re: Skipping a level in the data division

Thanks, Tom.

Now I understand what he did. He put all the elementary items at the 03 level and used the 02 levels to group related fields, something like this:

01  Employee-record.
        03 Clock               pic x(5).
	03 Name                pic x(20).
    02  Address.
        03   City              pic x(15).
        03   State-code        pic xx.
	03   Zip-code          pic x(10).
    02  Payroll-information.
        03  Marital-status     pic x.
        03  Dependents         pic s99.
        03  Additional-federal pic s9(5)v99.

He could have omitted the 02 levels and it wouldn't have made any difference.

I truly learn something new every day.