A super handy Hash class extension which allows you to manipulate it's keys based on a specific logic. It also adds the option to recursively affect all Hashes found in the structure. More under the cut

{required: true}.merge(optional: true)
# => {:required=>true, :optional=>true}

{required: true, optional: true}.merge(optional: false)
# => {:required=>true, :optional=>false}

#hash, #merge, #ruby

If your parse website with postal codes and from each page you get hash like this: { :street1 => [house1, house2], :street2 => [house3] ... } you need to merge this hashes into one. I saw a lot of bulky solutions, but here is the shortest:

array_of_hashes.inject(&:merge)

#ruby #hash