All of the Array functions have a preview where you can change a parameter prior to accepting the results except ArrayCrv and ArrayCrvOnSrf.
ArrayCrv does not have a preview. Once you set the last parameter it just does it.
ArrayCrvOnSrf does the action as soon as you specify a value for Divide or Multiple, but if you set the parameter again it does it again without removing the objects created by the previous action. Bug?