I am not able to achieve the desired results with the conventional Ruby methods to remove all duplicate objects from the array, user_list, below. Is there a smart way to solve this problem?
users = []
user_list.each do |u|
user = User.find_by_id(u.user_id)
users << user
#users << user unless users.include?(user) # does not work
end
#users = users.uniq # does not work
How about this?
users = User.find(user_list.map(&:user_id).uniq)
This has the additional benefit of being one database call instead of user_list.size database calls.
User.where(user_id: user_list.map(&:user_id)) which will lazily-execute the database query, and handles the uniq automatically.user_list.uniq!
This should remove all the duplicate value and keep the unique ones in user_list. I hope this is what you are looking for.
You can also use compact to remove nil objects as
MainMenu.first.second_sale_elements.each.map(&:sale_structure).compact.uniq
user_list.uniq! works thanks, but remember uniq! will return a nil object if no duplicates appear, so if you don't have a validator use uniq cuz it will return a new array.
Ruby uniq! documentation
Returns nil if no changes are made (that is, no duplicates are found).
uniqreally should work. Could you show the steps you took to test it and what your results were? What is the class of the objects in the user's array and how is their==operator defined? Is this Ruby on Rails?Rails 4orRails 3? Oh right, are you using rails at all? If not, what is theUserclass from?