Article: Q21964
Product(s): See article
Version(s): 2.00 2.01 3.00 4.00 4.00b 4.50
Operating System(s): MS-DOS
Keyword(s): ENDUSER | B_BasicCom | mspl13_basic
Last Modified: 11-JAN-1990
Problem:
I can dimension a single-dimensional dynamic integer array with
32,000 elements; however, I get the message "Subscript Out of Range"
dimensioning a two-dimensional integer array with only 30,000
elements. The following is an example:
Rem $dynamic
dim b%(32000) 'this is okay
dim c%(10,2850) 'this is also okay
dim a%(10,3000) ' this will give a "subscript out of range" error
Response:
The statement DIM A%(10,3000) exceeds the 64K size limit that
exists for each dynamic numeric array. In QuickBASIC Version 4.00 and
greater, you can compile with QB /AH or BC /AH to allow dynamic
numeric (or fixed-length string) arrays to exceed 64K. The /AH switch
is not implemented in QuickBASIC 3.00 and previous versions.
An array dimensioned DIM B%(32000) actually has 32,001 elements
because the counting begins at element 0 by default, and the array
will take up 64,002 bytes, since there are two bytes per integer
element.
You may change the default starting element to 1 with the OPTION
BASE 1 statement. An array dimensioned DIM C%(10,2850) actually has
31,361 elements (11 multiplied by 2,851) which would take up 62,722
bytes. An integer array dimensioned (10,3000) gives a "subscript out
of range" error because it has 33,011 elements, or 66,022 bytes, which
exceeds the dynamic numeric array size limit of 65,536 bytes (64K).
Note that there are 1,024 bytes per Kilobyte (K), therefore 64K
multiplied by 1024 bytes per Kilobyte equals 65,536 bytes.