OPTION BASE Statement Details
 
Syntax
  OPTION BASE n
 
The OPTION BASE statement is never required. It is used to change the
default lower bound for array subscripts.
 
The value of n must be either 0 or 1. The default base is 0. If the
following statement
 
  OPTION BASE 1
 
is executed, the lowest value an array subscript can have is 1.
 
  Note: DIM statement provides an easier, more flexible way to control
        the range of an array's subscripts. If the lower bound of an
        array subscript is not explicitly set, then OPTION BASE can
        be used to change the default lower bound to 1.
 
The OPTION BASE statement can be used only once in a module (source file)
and can only appear in the module-level code. An OPTION BASE statement
must be used before any arrays are dimensioned.
 
Chained programs may have an OPTION BASE statement if no arrays are passed
in COMMON between them or if the specified base is identical in the chained
programs. The chained-to program inherits the OPTION BASE value of the
chaining program if OPTION BASE is omitted in the latter.