Auto incrementing elements to Auto extending array

At a recent conference one of the attendees point out to me that my examples of using an auto-extending array only used it as the place for data when I fetched data from a SQL cursor. What about a scenario I want to load values into an auto-extending using a For group or Do loop?

I was surprised that I have not given an example of this scenario. This post remediates that oversight.

I wanted to keep my example program as simple as possible:

01 **free 02 dcl-s Array char(2) dim(*auto : 99) ; 03 dcl-s Counter uns(3) ; 04 for Counter = 1 to 10 ; 05 Array(*next) = %char(Counter) ; 06 endfor ; 07 dsply ('Elements = ' + %char(%elem(Array)) ) ; 08 *inlr = *on ;

Line 2: This is the array definition for the auto-extending array. The array has a maximum of 99 elements.

Line 3: This variable is going to be used to load the array.

Lines 4 – 6: I could not think of any simpler way to load the array than a For group.

Line 4: The For group will be performed 10 times.

Line 5: This is where the value from the variable Counter is loaded into the next element of the array. The array element is *NEXT, for an auto-extending array a new element is added to the array and then the value from Counter is moved into the new element.

Line 7: The Display operation code, DSPLY is used to display the number of elements in the array. The %ELEM BiF returns the number of array elements in the array.

After the program is created and then called this is what is displayed:

DSPLY Elements = 10

And to really prove that 10 elements were added to the array if I use debug and view the contents of the array at the end of the program I see:

ARRAY(1) = '1 ' ARRAY(2) = '2 ' ARRAY(3) = '3 ' ARRAY(4) = '4 ' ARRAY(5) = '5 ' ARRAY(6) = '6 ' ARRAY(7) = '7 ' ARRAY(8) = '8 ' ARRAY(9) = '9 ' ARRAY(10) = '10'

My oversight is now corrected.

 

This article was written for IBM i 7.5, and should work for some earlier releases too.