Simple demonstration
The following three
VBA modules try to demonstrate the effect of
option base on the creation of arrays:
without.bas
Without an explicition option base statement, arrays are created with their first index being 0.
option explicit
function arrayWithoutOptionBase() as variant() ' {
arrayWithoutOptionBase = array(0, 1, 2, 3)
end function ' }
with.bas
The following module specifies option base 1. So, arrays, by default, are created with their first index being 1.
option explicit
option base 1
function arrayWithOptionBase() as variant() ' {
arrayWithOptionBase = array("one", "two", "three", "four")
end function ' }
run.bas
The driver program calls the two functions and then checks the range of their indexes with the
lBound and uBound functions.
option explicit
sub main() ' {
dim array_0() as variant
dim array_1() as variant
array_0 = arrayWithoutOptionBase
array_1 = arrayWithOptionBase
debug.print "array_0 starts with index " & lBound(array_0) & " and ends with index " & uBound(array_0)
debug.print "array_1 starts with index " & lBound(array_1) & " and ends with index " & uBound(array_1)
debug.print ""
debug.print "array_0(2) = " & array_0(2)
debug.print "array_1(2) = " & array_1(2)
end sub ' }
'
' Program writes
'
' array_0 starts with index 0 and ends with index 3
' array_1 starts with index 1 and ends with index 4
'
' array_0(2) = 2
' array_1(2) = two