Reputation: 2974
I have a Hash as follows:
{'a' => [title: 'ab', path: 'cd'], 'b' => [title: 'ef', path: 'gh']}
Now lets say I have one title and wish to get the key from it...
i.e. if I have 'ef' and want 'b'
This is what I'm currently doing, but it seems extremely clunky...
def get_hash_key(hash)
hash.each do |k, h|
return k if h[0][:title] == 'ef'
end
end
h = {'a' => [title: 'ab', path: 'cd'], 'b' => [title: 'ef', path: 'gh']}
get_hash_key(h)
Is there another better way of doing this?
Upvotes: 0
Views: 53
Reputation: 110755
h = {'a' => [title: 'ab', path: 'cd'], 'b' => [title: 'ef', path: 'gh']}
#=> {"a"=>[{:title=>"ab", :path=>"cd"}], "b"=>[{:title=>"ef", :path=>"gh"}]}
h.each_with_object({}) { |(k,v),g| g[v.first[:title]] = k }['ef']
#=> "b"
or
h.each_with_object({}) { |(k,v),g| g[k] = v.first[:title] }.invert['ef']
#=> "b"
Upvotes: 1
Reputation: 121010
h = {'a' => [title: 'ab', path: 'cd'], 'b' => [title: 'ef', path: 'gh']}
h.select { |_,v| v[0][:title] == 'ef' }.keys
# => [
# [0] "b"
# ]
Upvotes: 2