2 array questions

[TriumphRacer]

I need some help initializing an array containing strings.

Here's the code:

DIM steady_job(1 TO 8) AS STRING => ("yes", "yes", "no", "no", _
"yes", "yes", "no", "no")


When I attempt to compile, I get:

compiling: idbcxxxx.bas -o idbcxxxx.asm

idbcxxxx.bas(75) : error 7: Expected ')', found: ','

DIM steady_job(1 TO 8) AS STRING => ("yes", "yes", "no", "no", _
^

Any idea what I'm doing wrong?

Next question. I'm attempting to add some statistical analysis to my engine program. The above is just a test case to test my math. Here's what I need to do. At _compile_ time, I have no idea how many arrays the user will need, whether the elements of the arrays will be numeric or string or mixed, or how many elements each array will have. How can I make the arrays *VERY* dynamic to cover just about all eventualities?

Thanks again in advance.
Bill
;-))

[v1ctor]

To initialize arrays use {}'s, ()'s are used with UDT's.

[arenth]

As far as dynamic arrays REDIM works rather nicely.

For instance

DIM steady_job() AS STRING

DIM jobCount as LONG

jobCount = 0

DO
--Something about handing user input--

'Add new job
REDIM PRESERVE steady_job(jobCount)
steady_job(jobCount) = userInput
jobCount +=1

LOOP

REDIM means REDIMension, PRESERVE will tell freebasic to non-destructively resize the array. This means any existing data will remain up to the length of the new array.

[TriumphRacer]

Whoops! Mark up question #1 to monitor resolution (not to mention age and eyesight ;-)) Went back and rechecked help files and found curly braces not paran. Had to squint.

In regards to 2nd question, I'm not sure if it was answered or not. Mayhaps I should restate.

When I compile the program, I will have no idea how many arrays the user will need. Could be 3 or 4, could be 15 or 20.

Neither will I have any idea how many elements each array will have. Maybe 2 or 3, maybe 75 or 80.

Nor will I have any idea whether or not the array elements will be numeric or string. In my math test example, I'm using text but it could just as well be a 3 or a 3.1419572 or a yes or no. I need to make it as flexible as possible.

Can I make the array name a variable? Then tack a number on the end: e.g. array1, array2, array3, ... arrayn.

Anyone familiar with the ID3 algorithm? That's what I'm trying to implement.

Thanks again.

Bill

[VirusScanner]

I'd read about pointers and using allocate/deallocate/reallocate. That way nothing is allocated in memory until you need it, and you can delete it if it isn't needed anymore.

[1000101]

In regards to 2nd question, I'm not sure if it was answered or not. Mayhaps I should restate.

When I compile the program, I will have no idea how many arrays the user will need. Could be 3 or 4, could be 15 or 20.

Neither will I have any idea how many elements each array will have. Maybe 2 or 3, maybe 75 or 80.

Nor will I have any idea whether or not the array elements will be numeric or string. In my math test example, I'm using text but it could just as well be a 3 or a 3.1419572 or a yes or no. I need to make it as flexible as possible.

Can I make the array name a variable? Then tack a number on the end: e.g. array1, array2, array3, ... arrayn.

Basically what you want is a linked list. This way you can allocate new "variables" as well and keep track of them in a simple manner. You may also want to look into hashing algorythms, which, may provide a better solution then linked lists.

[yetifoot]

i was wondering this recently

Code: Select all

DIM steady_job(8) AS STRING => {"yes", "yes", "no", "no", _
"yes", "yes", "no", "no"}

gives me error

cannot initialize dynamic arrays

so i had to do something like this

Code: Select all

DIM steady_job(8) AS ZSTRING * 20 => {"yes", "yes", "no", "no", _
"yes", "yes", "no", "no"}

although i didnt like this because in a large one there will be wastage due to all elements being len 20

[VirusScanner]

This works for me:

Code: Select all

dim as zstring ptr test(0 to 1) => {strptr("hi"), strptr("not another one")}

print *test(0), *test(1)
sleep

[D.J.Peters]

Next question. ... Here's what I need to do. At _compile_ time, I have no idea how many arrays the user will need, whether the elements of the arrays will be numeric or string or mixed, or how many elements each array will have. How can I make the arrays *VERY* dynamic to cover just about all eventualities?

build your own dynamic variant data type (in size too).

If you need more instructions let me know.

Joshy

[DrV]

You could also do:

Code: Select all

DIM steady_job(8) AS ZSTRING ptr => {strptr("yes"), strptr("yes"), strptr("no"), strptr("no"), _
strptr("yes"), strptr("yes"), strptr("no"), strptr("no")} 

EDIT: oops, looks like some people beat me to it already :)

[v1ctor]

Btw, just @ is enough, literal strings are zstring's so STRPTR has the same effect as VARPTR (or the @ address of operator).

Code: Select all

DIM steady_job(8) AS ZSTRING ptr => {@"yes", @"yes", @"no", @"no", @"yes", @"yes", @"no", @"no"}

[TriumphRacer]

[quote]
build your own dynamic variant data type (in size too).

If you need more instructions let me know.

Joshy
[/quote]

I'd be *very* interested in some help on this. As I've stated before, I'm not a pro programmer, just an amateur and I think I'm getting in over my head but the concept is a good one.

Thanks to all for bearing with a neophyte!

Bill
;-)))

[D.J.Peters]

Hello TriumphRacer,
it exist many ways to implement an varaiant data type and i can post a version next weekend but it will help if you tell what is the main usage for example dynamic arrays of varaiant to expand database reading or what ever.

for what do you need it?

Joshy

[stylin]

How can I make the arrays *VERY* dynamic to cover just about all eventualities?

With generic programming paradigms - in C-style languages (C, Pascal, etc.) this involves writing MACROs. You parameterize the type of element you need to store in the array, and let the compiler do the rest - duplicating virtually identical code for any and all element types you wish to include.

I'm in the process of writing a set of tutorials on this subject, but here is an incomplete implementation of a generic array, which can be expanded to make it dynamically resizable upon adding/removing elements. It might be enough to get you started.

[syzygy]

To answer your problem, I recommend setting up an array of arrays. If you do that dynamically, you can resize the number of data sets you want to evaulate by resizing the "master array".

Each array within the master array could be composed of unions. The unions in turn hold members, one for each of the data types (string, int, real, ...) you want to examine. For each of the arrays, record the array's data type and the number of entries in the data set, and you should be halfway there.

I recommend checking out the TYPE, UNION and DIM/REDIM entries in the online help.

Cheers, and good luck,

syzygy