Controller:
@user_location = Country.joins(:user).order(:name).compact.uniq
View (haml):
- @user_location.each do |user|
%li= user.name
At this point, all duplicate elements of the array are deleted (uniq).
How can I display the number of repetitive elements in the array? For example: if my array has
One Two Two Three Four
then I need to show
One Two (2) Three Four
I would expect that something like this might work:
# in the controller (this returns a hash)
@locations = Country.joins(:user).order(:name).group(:name).count
# in your view
- @locations.each do |name, count|
%li
= name
= "(#{count})" if count > 1
You need group_by + map. Like this:
array.group_by(&:itself).map do |k, v|
{ value: k, count: v.length }
end
You will have array of hashes like this: {value: 'Two', count: 2}.
You can return data in any desired way. However, it's much better to get grouped records directly from SQL.
group_by{ |x| x} with group_by(&:itself) to improve readabilityv > 1 ? "#{k} (#{v})" : k.You can iterate through using each_with_object, counting elements as they're assigned to a hash key. For example:
array = %w(One Two Two Three Four)
counts = array.each_with_object(Hash.new(0)) do |el, hash|
hash[el] += 1
end
# => {"One"=>1, "Two"=>2, "Three"=>1, "Four"=>1}
counts.map { |k, v| v > 1 ? "#{k} (#{v})" : k }
# => ["One", "Two (2)", "Three", "Four"]
Does that look like what you're after? If not, or you've any questions, let me know!
%w[One Two Two Three Four].
group_by{|x|x}.
map{|k, v|[k,v.count>1?" (#{v.count})":nil]}.
map(&:compact).
map(&:join)
#⇒ ["One", "Two (2)", "Three", "Four"]
