Synopsis:
   $getarrays()

Technical:
   This function displays all existing arrays created by $setitem().

Practical:
   This function is used to show all current arrays.  his might be useful
   for modifying data in multiple arrays, when it is not known precisely
   which ones exist at the moment in question.

Returns:
   list of array names, or nothing if none are set

See Also:
   Arrays(7); setitem(6)

