How to merge multiple hashes in Ruby?

You could do it like this:

h, h2, h3  = { a: 1 }, { b: 2 }, { c: 3 }
a  = [h, h2, h3]

p Hash[*a.map(&:to_a).flatten] #= > {:a=>1, :b=>2, :c=>3}

Edit: This is probably the correct way to do it if you have many hashes:

a.inject{|tot, new| tot.merge(new)}
# or just
a.inject(&:merge)