The system variable ŒIO has a numeric value of 0 or 1 which states whether the origin for counting is 0 or 1. This determines whether the first element in a count is element 0 or element 1. The default is 1. A new value can be assigned. ŒIO may be localised in a function.
ŒIO„1 ¼4 1 2 3 4 ŒIO„0 ¼4 0 1 2 3
Operations which involve indexing of arrays ([ ]) are affected by ŒIO.
A number of functions are affected by ŒIO:
¼ ? “ ” ³ œ Þ
Functions and operators which use axis specifications are also affected:
² ´ / š \ ™ , † ‡ › œ
and finally, the line number returned by ŒFX if an error occurs is affected by ŒIO.