%%[
var @arr, @e, @arrPos, @count, @lastVal

set @arr = "red|yellow|black|white|green"
set @e = BuildRowsetFromString(@arr,"|")
set @count = rowcount(@e)

if @count > 0 then

    set @arrPos = row(@e, @count) /* get row last element */
    set @lastVal = field(@arrPos,1)
    outputline(concat("<br>lastVal: ",@lastVal))

else

  outputline(concat("<br>empty array"))

endif
]%%