Array#uniq with Hash elements... can't remove duplicates
andrea
I am having some trouble trying to remove duplicate data from an array
of hashes. I've read on the pickaxe book that Array#uniq detects
duplicates using the eql? method on the elements, but it doesn't seem to
work even if I monkeypatch the Hash class:
class Hash
def eql? other
self == other
end
end
a={:foo=>'bar'}
b={:foo=>'bar'}
array=[a,b]
a.eql? b
=> true
array.uniq
=> [{:foo=>"bar"}, {:foo=>"bar"}]
Of course, I'd like to get only [{:foo=>"bar}] as a result. Thanks in
advance for any help...
Andrea
--
Marcin Mielżyński
> Hello,
>
> I am having some trouble trying to remove duplicate data from an array
> of hashes. I've read on the pickaxe book that Array#uniq detects
> duplicates using the eql? method on the elements, but it doesn't seem to
> work even if I monkeypatch the Hash class:
>
> class Hash
> def eql? other
> self == other
> end
> end
you also need to define #hash method:
class Hash
def eql? other
self == other
end
def hash
h = 0
each_pair do |k, v|
h ^= k.hash
h *=137
h ^= v.hash
end
h
end
end
lopex
andrea
> you also need to define #hash method:
Thank you !
Andrea
--