Is there a way to initialize an object through a hash?

You can define an initialize function on your class:

class A
  attr_accessor :b,:c,:d
  def initialize(h)
    h.each {|k,v| public_send("#{k}=",v)}
  end
end

Or you can create a module and then “mix it in”

module HashConstructed
 def initialize(h)
  h.each {|k,v| public_send("#{k}=",v)}
 end
end

class Foo
 include HashConstructed
 attr_accessor :foo, :bar
end

Alternatively you can try something like constructor