GWBASIC User's Manual

GW-BASIC User's Guide
DIM Statement
Purpose:
To specify the maximum values for array variable subscripts and allocate storage accordingly.
Syntax:
DIM variable(subscripts)[,variable(subscripts)]...
Comments:
If an array variable name is used without a DIM statement, the maximum value of its subscript(s)
is assumed to be 10. If a subscript greater than the maximum specified is used, a "Subscript
out of range" error occurs.
The maximum number of dimensions for an array is 255.
The minimum value for a subscript is always 0, unless otherwise specified with the OPTION
BASE statement.
An array, once dimensioned, cannot be re-dimensioned within the program without first
executing a CLEAR or ERASE statement.
The DIM statement sets all the elements of the specified arrays to an initial value of zero.
Examples:
10 DIM A(20)
20 FOR I=0 TO 20
30 READ A(I)
40 NEXT I
This example reads 21 DATA statements elsewhere in the program and assigns their values to A
(0) through A(20), sequentially and inclusively. If the A array is single precision (default
accuracy) then line 10 will allocate 84 bytes of memory to this array (4 bytes times 21 elements).
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