I have some simple code that looks like this:
fruit.each do |c|
c.each do |key, value|
puts value
end
end
This works fine, but it feels un-ruby like. My goal is to take this array:
[{"fruit_id"=>"1"}, {"fruit_id"=>"2"}, {"fruit_id"=>"3"}]
And convert it to this:
[ "1", "2", "3" ]
Thoughts?
If it's in Rails or if you have to_proc defined, you can go a little bit shorter than @toholio's solution:
arr = [{"fruit_id"=>"1"}, {"fruit_id"=>"2"}, {"fruit_id"=>"3"}]
out = arr.map(&:values).flatten # => ["1", "2", "3"]
So you want each hash to be converted to its values then joined with the values from the other hashes?
in = [{"fruit_id"=>"1"}, {"fruit_id"=>"2"}, {"fruit_id"=>"3"}]
out = in.map{ |item| item.values }.flatten
out will then be ["1","2","3"].
@wombleton @aronchick I suggest to use "flat_map(&:values)" instead "map(&:values).flatten" for better performance.
arr = [{"fruit_id"=>"1"}, {"fruit_id"=>"2"}, {"fruit_id"=>"3"}]
out = arr.flat_map(&:values)
Take a look here for more info: http://gistflow.com/posts/578-use-flat_map-instead-of-map-flatten
if you use map!, you don't create another array in memory
a.map! {|h| h.values}.flatten
this can be also written as
a.map!(&:values).flatten!
also looking at the comments, theres a method in ruby 1.9.3 called flat_map (http://ruby-doc.org/core-1.9.3/Enumerable.html#method-i-flat_map) that will do the map and the flatten in one call.
a.flat_map(&:values)
a.inject([]) { |mem,obj| mem += obj.values }
It wouldn't change much, but you could use map:
x.map do |fruit|
fruit.each { |k,v| puts v }
end
