Try on a nested hash

try_hash.rb

# http://rubyquicktips.tumblr.com/post/4601358354/using-try-with-a-hash-to-check-existence-of-a-key

hsh = { :existing_key =>
            {
               :existing_sub_key => :value
            }
      }

hsh.try(:[], :existing_key).try(:[], :existing_sub_key)
# => :value
 
hsh.try(:[], :unexisting_key).try(:[], :whatever) || "Default nested value"
# => "Default nested value"

hsh[:unexisting_key][:whatever] rescue 'Default'
# => "Default"