Ruby: adding a new element to each array in an array, such that the new element is the downcased version of an existing element -

if

@users = user.all.group_by(&:iso).map{|k,v| [k, v.count]} 

returns

 [["gb", 1], ["gi", 3], ["bd", 1]] 

why can't this

 @users = user.all.group_by(&:iso).map{|k,v| [k, v.count, k.downcase]} 

to

[["gb", 1, "gb"], ["gi", 3, "gi"], ["bd", 1, "bd"]] 

i getting error

      undefined method `downcase' nil:nilclass 

how this.

if

   @user_json = user.all.group_by(&:iso).map{|k,v| [k, v.count, k.inspect]} 

i

   [["gb", 1, "\"gb\""], ["gi", 3, "\"gi\""], ["bd", 1, "\"bd\""] 

and

  @user_json = user.all.group_by(&:iso).map{|k,v| [k, v.count, k.inspect.downcase]}   [["gb", 1, "\"gb\""], ["gi", 3, "\"gi\""], ["bd", 1, "\"bd\""] 

v. confused

for more details - works (but if wrong , can't explain why)

i trying build json array structure:

   [{"code":"gb","value":1,"flag":"gb"},{"code":"gi","value":3,"flag":"gi"},{"code":"bd","value":1,"flag":"bd"}] 

my controller code

     def global_chart           @user_json = user.all.group_by(&:iso).map{|k,v| [k, v.count, k.to_s.downcase]}.map {|c, v | ["code" => c, "value" => v, "flag" => c.to_s.downcase]}.flatten.to_json           render 'users/charts/global'     end 

this works ( @user_json variable has right structure) can't explain behaviour above....

your code

@users = user.all.group_by(&:iso).map{ |k,v| [k, v.count] } 

is absolutely valid , output shows have got 3 iso groups. then

@users = user.all.group_by(&:iso).map{ |k,v| [k, v.count, k.downcase] } 

is absolutely valid code well. error undefined method 'downcase' nil:nilclass tells 1 of iso values nil. not true first example output.

after that, third snippet

user.all.group_by(&:iso).map{ |k,v| [k, v.count, k.inspect.downcase] } 

which again correct, returns same output first 1 (i mean same sample of iso).

so somewhere in code bug. believe close provided piece of code. show whole controller's code see maybe problem on surface.