but it does not change the Market.marketarray to ["blue","green"]
it just keeps the original array as if it did not happen
if i do this @marketobject.marketarray = ["1","1"] @marketobject.save!
then it saves the marketarray to ["1","1"]
call @marketobject.marketarray_will_change! before you save (you must
do this when you change objects in place (so same thing if you had a
string attribute and did .gsub!)