OPTION BASE

The OPTION BASE statement is used to set the default lower bound of arrays.

Syntax

OPTION BASE {0|1}

Description

• This statement affects array declarations where the lower bound of a dimension is not specified.
• When used, OPTION BASE must come before any array declarations (DIM) to be affected.
• By default, the lower bound for arrays is zero, and may be changed to one using the statement.
• Otherwise, arrays will be dimensioned from element 0 if you DIM just the upper bounds.
• You can also set other array boundaries by using TO in the DIM declaration such as DIM array(5 TO 10)

Example(s)

Set the default lower bound for array declarations to one.

OPTION BASE 1

' Declare a 5-element one-dimensional array with element indexes of one through five.
DIM array(5) AS INTEGER

PRINT LBOUND(array)

 1

Set the default lower bound for array declarations to zero.

OPTION BASE 0

' Declare an 18-element two-dimensional array with element indexes of zero through two 
' for the first dimension, and 10 through 15 for the second dimension.
DIM array(2, 10 to 15) AS INTEGER

PRINT LBOUND(array, 1)
PRINT LBOUND(array, 2)

 0
 10

See Also

• Arrays, LBOUND, UBOUND
• DIM, REDIM, STATIC, COMMON