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Q39384: INPUT to Out of Range Array Element Can Hang; or Bad Value

Article: Q39384
Product(s): See article
Version(s): 4.00 4.00b
Operating System(s): MS-DOS
Keyword(s): ENDUSER | buglist4.00 buglist4.00b fixlist4.50 B_BasicCom | mspl13_basic
Last Modified: 21-DEC-1988

When an array element in an INPUT statement is out of range, the
QuickBASIC editor may hang, instead of producing a "Subscript out of
range" error message. (The problem occurs when the program explicitly
dimensions the array or uses the default values.)

The program also fails if compiled to an executable file. If compiled
with the DEBUG option /d, the program will hang, similar to the
QuickBASIC editor. Without the /d option, the results will vary from
incorrect values being displayed to the machine hanging.

This information applies to QuickBASIC Version 4.00 and 4.00b, and the
BASIC Compiler Version 6.00 and 6.00b (buglist6.00, buglist6.00B). This
problem was corrected in QuickBASIC Version 4.50.

To work around the problem you should avoid assigning array elements
that are outside of the allowed range.

The following two code examples demonstrate the problem:

REM *** EXAMPLE 1: Using the DEFAULT array size limits, 0 to 10
FOR a = 1 TO 20
    INPUT "ENTER NUMBER "; b(a)
NEXT a

REM *** EXAMPLE 2: Using DIM statement to explicitly set limits
DIM b(10)
FOR a = 1 TO 20
    INPUT "ENTER NUMBER "; b(a)
NEXT a

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