% irb
irb(main):001:0> x = 2
=> 2
irb(main):002:0> x.methods
=> [:%, :&, :*, :+, :-, :/, :<, :>, :^, :|, :~, :-@, :**, :<=>, :<<, :>>, :<=, :>=, :==, :===, :[], :inspect, :size, :succ, :to_int, :to_s, :to_i, :to_f, :next, :div, :upto, :chr, :ord, :coerce, :divmod, :fdiv, :modulo, :remainder, :abs, :magnitude, :integer?, :floor, :ceil, :round, :truncate, :odd?, :even?, :downto, :times, :pred, :bit_length, :digits, :to_r, :numerator, :denominator, :rationalize, :gcd, :lcm, :gcdlcm, :+@, :eql?, :singleton_method_added, :i, :real?, :zero?, :nonzero?, :finite?, :infinite?, :step, :positive?, :negative?, :quo, :arg, :rectangular, :rect, :polar, :real, :imaginary, :imag, :abs2, :angle, :phase, :conjugate, :conj, :to_c, :between?, :clamp, :instance_of?, :kind_of?, :is_a?, :tap, :public_send, :remove_instance_variable, :singleton_method, :instance_variable_set, :define_singleton_method, :method, :public_method, :extend, :to_enum, :enum_for, :=~, :!~, :respond_to?, :freeze, :object_id, :send, :display, :nil?, :hash, :class, :singleton_class, :clone, :dup, :itself, :taint, :tainted?, :untaint, :untrust, :untrusted?, :trust, :frozen?, :methods, :singleton_methods, :protected_methods, :private_methods, :public_methods, :instance_variable_get, :instance_variables, :instance_variable_defined?, :!, :!=, :__send__, :equal?, :instance_eval, :instance_exec, :__id__]
irb(main):003:0>
irb(main):004:0* x.denominator
=> 1
irb(main):005:0> y = 'hello'
=> "hello"
irb(main):006:0> y.methods
=> [:include?, :%, :*, :+, :to_c, :unicode_normalize, :unicode_normalize!, :unicode_normalized?, :count, :partition, :unpack, :unpack1, :sum, :next, :casecmp, :casecmp?, :insert, :bytesize, :match, :match?, :succ!, :+@, :-@, :index, :rindex, :<=>, :replace, :clear, :upto, :getbyte, :==, :===, :setbyte, :=~, :scrub, :[], :[]=, :chr, :scrub!, :dump, :byteslice, :upcase, :next!, :empty?, :eql?, :downcase, :capitalize, :swapcase, :upcase!, :downcase!, :capitalize!, :swapcase!, :hex, :oct, :split, :lines, :reverse, :chars, :codepoints, :prepend, :bytes, :concat, :<<, :freeze, :inspect, :intern, :end_with?, :crypt, :ljust, :reverse!, :chop, :scan, :gsub, :ord, :start_with?, :length, :size, :rstrip, :succ, :center, :sub, :chomp!, :sub!, :chomp, :rjust, :lstrip!, :gsub!, :chop!, :strip, :to_str, :to_sym, :rstrip!, :tr, :tr_s, :delete, :to_s, :to_i, :tr_s!, :delete!, :squeeze!, :each_line, :squeeze, :strip!, :each_codepoint, :lstrip, :slice!, :rpartition, :each_byte, :each_char, :to_f, :slice, :ascii_only?, :encoding, :force_encoding, :b, :valid_encoding?, :tr!, :encode, :encode!, :hash, :to_r, :<, :>, :<=, :>=, :between?, :clamp, :instance_of?, :kind_of?, :is_a?, :tap, :public_send, :remove_instance_variable, :singleton_method, :instance_variable_set, :define_singleton_method, :method, :public_method, :extend, :to_enum, :enum_for, :!~, :respond_to?, :object_id, :send, :display, :nil?, :class, :singleton_class, :clone, :dup, :itself, :taint, :tainted?, :untaint, :untrust, :untrusted?, :trust, :frozen?, :methods, :singleton_methods, :protected_methods, :private_methods, :public_methods, :instance_variable_get, :instance_variables, :instance_variable_defined?, :!, :!=, :__send__, :equal?, :instance_eval, :instance_exec, :__id__]
irb(main):007:0>
irb(main):008:0* y.length
=> 5
irb(main):009:0>