Hashes are indexed using the square brackets ([]). Just as arrays. But instead of indexing with the numerical index, hashes are indexed using either the string literal you used for the key, or the symbol.
So if your hash is similar to
hash = { "key1" => "value1", "key2" => "value2" }
you can access the value with
hash["key1"]
or for
hash = { :key1 => "value1", :key2 => "value2"}
or the new format supported in Ruby 1.9
hash = { key1: "value1", key2: "value2" }
you can access the value with
hash[:key1]
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