Ruby on Railsの面白いメソッド

irb(main):001:0> string="string"
=> "string"
irb(main):002:0> string.methods
=> [:to_json, :squish!, :remove!, :truncate_words, :camelcase, :titlecase,
 :parameterize, :from, :mb_chars, :is_utf8?, :%, :*, :+, :html_safe,
 :strip_heredoc, :to_c, :exclude?, :indent!, :truncate, :remove,
 :shellsplit, :to, :shellescape, :+@, :-@, :<=>, :<<, :==, :===, :=~,
 :[], :[]=, :empty?, :eql?, :freeze, :inspect, :intern, :inquiry, :length,
 :size, :succ, :pathmap, :to_str, :to_sym, :to_s, :to_i, :to_r, :to_f,
 :pathmap_explode, :pathmap_partial, :indent, :pathmap_replace, :hash,
 :include?, :at, :last, :classify, :acts_like_string?, :ext, :to_blob,
 :as_json, :ends_with?, :count, :blank?, :partition, :in_time_zone,
 :first, :to_datetime, :sum, :next, :casecmp, :casecmp?, :insert,
 :bytesize, :match, :match?, :succ!, :next!, :upto, :index, :rindex,
 :replace, :clear, :chr, :getbyte, :setbyte, :byteslice, :scrub, :scrub!,
 :squish, :dump, :undump, :to_d, :upcase, :to_date, :downcase, :swapcase,
 :upcase!, :capitalize, :capitalize!, :encode, :downcase!, :oct,
 :swapcase!, :lines, :bytes, :split, :codepoints, :grapheme_clusters,
 :reverse, :reverse!, :hex, :underscore, :crypt, :ord, :prepend, :chars,
 :scan, :start_with?, :end_with?, :center, :sub, :gsub, :chop, :chomp,
 :strip, :concat, :lstrip, :delete_prefix, :delete_suffix, :rstrip,
 :gsub!, :chop!, :chomp!, :rjust, :strip!, :upcase_first, :rstrip!,
 :tableize, :ljust, :sub!, :to_time, :delete, :foreign_key,
 :delete_suffix!, :lstrip!, :tr_s, :delete_prefix!, :each_line,
 :safe_constantize, :tr_s!, :delete!, :squeeze!, :tr!, :tr, :slice,
 :slice!, :squeeze, :each_byte, :valid_encoding?, :each_codepoint,
 :each_grapheme_cluster, :ascii_only?, :b, :rpartition, :encoding,
 :unicode_normalized?, :unicode_normalize!, :camelize, :each_char,
 :force_encoding, :dasherize, :constantize, :humanize, :singularize,
 :deconstantize, :encode!, :pretty_print, :titleize, :pluralize,
 :unicode_normalize, :demodulize, :starts_with?, :unpack, :unpack1,
 :to_json_raw_object, :to_json_raw, :<=, :>=, :between?, :<, :>,
 :clamp, :`, :html_safe?, :with_options, :acts_like?, :present?, :in?,
 :to_param, :presence, :presence_in, :duplicable?, :to_query,
 :instance_values, :instance_variable_names, :deep_dup, :to_yaml,
 :pretty_print_cycle, :pretty_print_inspect,
 :pretty_print_instance_variables, :load_dependency, :require_or_load,
 :unloadable, :require_dependency, :try!, :try, :instance_variable_set,
 :instance_variable_defined?, :remove_instance_variable, :instance_of?,
 :kind_of?, :is_a?, :tap, :instance_variable_get, :singleton_method,
 :method, :public_method, :define_singleton_method, :public_send,
 :class_eval, :extend, :gem, :byebug, :remote_byebug, :debugger,
 :to_enum, :enum_for, :pretty_inspect, :!~, :respond_to?,
 :object_id, :send, :display, :nil?, :class, :singleton_class,
 :clone, :dup, :itself, :yield_self, :taint, :tainted?, :untaint,
 :untrust, :untrusted?, :trust, :frozen?, :methods, :singleton_methods,
 :protected_methods, :private_methods, :public_methods,
 :instance_variables, :!, :equal?, :instance_eval, :instance_exec,
 :!=, :__id__, :__send__]

irb(main):001:0> integer=1
=> 1
irb(main):002:0> integer.methods
=> [:to_s, :to_json, :-@, :**, :<=>, :upto, :<<, :<=, :>=, :==, :chr, :===,
 :>>, :[], :to_d, :to_bn, :%, :&, :inspect, :+, :ord, :-, :numerator, :/,
 :*, :rationalize, :gcd, :lcm, :gcdlcm, :denominator, :size, :succ,
 :multiple_of?, :<, :>, :months, :years, :to_int, :coerce, :divmod,
 :to_i, :fdiv, :modulo, :remainder, :abs, :magnitude, :month, :integer?,
 :ordinalize, :year, :to_r, :floor, :ceil, :round, :truncate, :to_f, :^,
 :odd?, :even?, :allbits?, :anybits?, :nobits?, :downto, :times, :pred,
 :pow, :bit_length, :digits, :ordinal, :next, :div, :|, :~, :+@,
 :pretty_print, :minute, :weeks, :hours, :minutes, :eql?, :bytes,
 :kilobytes, :kilobyte, :megabyte, :gigabytes, :gigabyte, :terabytes,
 :singleton_method_added, :terabyte, :week, :fortnights, :fortnight,
 :arg, :in_milliseconds, :exabytes, :exabyte, :rectangular, :rect, :polar,
 :real, :imaginary, :imag, :abs2, :angle, :phase, :conjugate, :to_c,
 :second, :conj, :seconds, :pretty_print_cycle, :as_json, :i, :real?,
 :zero?, :nonzero?, :finite?, :infinite?, :step, :positive?, :negative?,
 :blank?, :hour, :day, :petabytes, :byte, :days, :html_safe?, :clone,
 :dup, :petabyte, :quo, :megabytes, :between?, :clamp, :`, :with_options,
 :acts_like?, :present?, :in?, :to_param, :presence, :presence_in,
 :duplicable?, :to_query, :instance_values, :instance_variable_names,
 :deep_dup, :to_yaml, :pretty_print_inspect,
 :pretty_print_instance_variables, :load_dependency, :require_or_load,
 :unloadable, :require_dependency, :try!, :try, :instance_variable_set,
 :instance_variable_defined?, :remove_instance_variable, :instance_of?,
 :kind_of?, :is_a?, :tap, :instance_variable_get, :singleton_method,
 :method, :public_method, :define_singleton_method, :public_send,
 :class_eval, :extend, :gem, :byebug, :remote_byebug, :debugger,
 :to_enum, :enum_for, :pretty_inspect, :=~, :!~, :respond_to?,
 :freeze, :object_id, :send, :display, :nil?, :hash, :class,
 :singleton_class, :itself, :yield_self, :taint, :tainted?, :untaint,
 :untrust, :untrusted?, :trust, :frozen?, :methods, :singleton_methods,
 :protected_methods, :private_methods, :public_methods,
 :instance_variables, :!, :equal?, :instance_eval, :instance_exec,
 :!=, :__id__, :__send__]

irb(main):014:0> "man".pluralize
=> "men"
irb(main):015:0> "man".pluralize(1)
=> "man"
irb(main):016:0> "man".pluralize(2)
=> "men"
irb(main):017:0> helper.pluralize(0,"man")
=> "0 men"
irb(main):018:0> helper.pluralize(1,"man")
=> "1 man"

irb(main):019:0> helper.pluralize(3,"woman",locale: :en)
=> "3 women"

irb(main):020:0> [1,2,3,4,5].shuffle
=> [3, 4, 2, 5, 1]
irb(main):021:0> ["a","b","c"].shuffle
=> ["c", "b", "a"]