(get [4 5 6] -1 ) # => nil (in [4 5 6] -1 42 ) # error (get-in [4 5 6] [-1] 42 ) # => 42 (get {:a 1} -1 ) # => nil (in {:a 1} -1 42 ) # => 42 (get-in {:a 1} [-1] 42 ) # => 42