Ref. WGR Chapter 7, Built-in essentials
42 (Fixnum)3.14159 (Float)truefalse"apple"'banana':apple/fo*/i["apple", "banana"](1..10){:apple => 'red', :banana => 'yellow'}{apple: 'red', banana: 'yellow'}to_i converts to integerto_f converts to floatto_s converts to stringto_a converts to arrayto_sym converts to symbolto_s in your UIto_s is insufficient and therefore uselessdisplay_name
inspectinspect produces a debug-ready representation of the object