Using numbers to access elements in arrays

[Devin Asay]

Correct me if I'm wrong...

It seems to me that Rev's implementation of arrays is not typical as 
compared to lower level languages. It seems to be more of a hash table 
(like in Java). In other words, you store data in arrays by associating 
each piece of data with a named key, rather than placing the data in 
enumerated elements. So when you put data into an array based on a 
number, like this:

   put "stuff" into myArray[1]

...you are essentially creating a key named "1", not placing the data 
in the first element of the array.

This creates problems under certain conditions. Say I want to put data 
into an array so that it is in a certain order. If I do it like this 
(notice I do it out of order):

   put "stuff" into myArray[1]
   put "junk" into myArray[2]
   put "nonsense" into myArray[4]
   put "fluff" into myArray[5]
   put "rubbish" into myArray[3]

... then I use a repeat loop to fetch it:

   repeat with i = 1 to 5
     put myArray[i] & space after aVar
   end repeat

This works okay, yielding: stuff junk rubbish nonsense fluff

However, there are situations where this leads to problems; 
specifically in using the rev database calls. I did something like this 
(notice out of order again--this was necessitated by my script 
structure):

   put "stuff" into myArray[1]
   put "junk" into myArray[2]
   put "nonsense" into myArray[4]
   put "fluff" into myArray[5]
   put "rubbish" into myArray[3]

Then I wanted to use this array to update data in a mySQL table. So I 
used the revExecuteSQL command like this (text wrapping alert):

   revExecuteSQL connectionID,"update testlog set 
quescorrect=quescorrect+:1, quesTotal=quesTotal+:2, t1_err=t1_err+:3, 
t2_err=t2_err+:4, t3_err=t3_err+:5 where studID = 1","myArray"

What SEEMS to be happening--I'm still trying to pin it down--is that 
the revExecuteSQL command is grabbing elements from the array in the 
order in which they were created--traditional array 
behavior--regardless of the key names (which happen to be numerals) 
that I assigned to them earlier. So what ends up in the table is in 
this order:

  stuff junk nonsense fluff rubbish

Am I right here? Is rev assigning literal values "1", "2", "3", etc. as 
key names, but the revExecuteSQL command is grabbing data from the 
variable by counting elements in the order they were created? This is 
causing me fits in one of my projects. If I can understand how it works 
I'll know if I can use this approach, or if I need to retreat and try a 
different approach to updating my database table.

Thanks.

Devin Asay
Humanities Technology and Research Support Center
Brigham Young University