--- !ruby/object:RI::MethodDescription aliases: [] block_params: comment: - !ruby/struct:SM::Flow::P body: Returns the key for a given value. If not found, returns nil. - !ruby/struct:SM::Flow::VERB body: " h = { "a" => 100, "b" => 200 }\n h.index(200) #=> "b"\n h.index(999) #=> nil\n" full_name: Hash#index is_singleton: false name: index params: | hsh.index(value) => key visibility: public