在Ruby中打印类的所有方法名称？
如果我想列出类的所有方法，我可以使用Class_Name.methods ，例如，列出FixNum类中的所有方法：
> 5.methods => [:to_s, :-@, :+, :-, :*, :/, :div, :%, :modulo, :divmod, :fdiv, :**, :abs, :magnitude, :==, :===, :, :>, :>=, :<, :<=, :~, :&, :|, :^, :[], :<>, :to_f, :size, :zero?, :odd?, :even?, :succ, :integer?, :upto, :downto, :times, :next, :pred, :chr, :ord, :to_i, :to_int, :floor, :ceil, :truncate, :round, :gcd, :lcm, :gcdlcm, :numerator, :denominator, :to_r, :rationalize, :singleton_method_added, :coerce, :i, :+@, :eql?, :quo, :remainder, :real?, :nonzero?, :step, :to_c, :real, :imaginary, :imag, :abs2, :arg, :angle, :phase, :rectangular, :rect, :polar, :conjugate, :conj, :between?, :nil?, :=~, :!~, :hash, :class, :singleton_class, :clone, :dup, :initialize_dup, :initialize_clone, :taint, :tainted?, :untaint, :untrust, :untrusted?, :trust, :freeze, :frozen?, :inspect, :methods, :singleton_methods, :protected_methods, :private_methods, :public_methods, :instance_variables, :instance_variable_get, :instance_variable_set, :instance_variable_defined?, :instance_of?, :kind_of?, :is_a?, :tap, :send, :public_send, :respond_to?, :respond_to_missing?, :extend, :display, :method, :public_method, :define_singleton_method, :object_id, :to_enum, :enum_for, :equal?, :!, :!=, :instance_eval, :instance_exec, :__send__, :__id__]
这个清单真的很难读。 我也试过5.methods.sort但这并没有让它更具可读性。
我经常在日常编程中使用方法列表。 有没有办法漂亮打印这个，所以它变得更容易阅读？
试试这个单行：
puts 5.methods.sort
我喜欢使用awesome_print 。 作为奖励，它为您提供彩色输出，方法和它们来自哪里：
1.9.3-p125 :001 > require 'ap' => true 1.9.3-p125 :002 > ap 5.methods; 0 [ [ 0] !() Fixnum (BasicObject) [ 1] !=(arg1) Fixnum (BasicObject) [ 2] !~(arg1) Fixnum (Kernel) [ 3] %(arg1) Fixnum [ 4] &(arg1) Fixnum [ 5] *(arg1) Fixnum [ 6] **(arg1) Fixnum [ 7] +(arg1) Fixnum [ 8] +@() Fixnum (Numeric) [ 9] -(arg1) Fixnum [ 10] -@() Fixnum [ 11] /(arg1) Fixnum [ 12] <(arg1) Fixnum [ 13] <<(arg1) Fixnum [ 14] <=(arg1) Fixnum [ 15] <=>(arg1) Fixnum [ 16] ==(arg1) Fixnum [ 17] ===(arg1) Fixnum [ 18] =~(arg1) Fixnum (Kernel) [ 19] >(arg1) Fixnum [ 20] >=(arg1) Fixnum [ 21] >>(arg1) Fixnum [ 22] [](arg1) Fixnum [ 23] ^(arg1) Fixnum [ 24] __id__() Fixnum (Kernel) [ 25] __send__(*arg1) Fixnum (BasicObject) [ 26] abs() Fixnum [ 27] abs2() Fixnum (Numeric) [ 28] ai(*options) Fixnum (Kernel) [ 29] angle() Fixnum (Numeric) [ 30] arg() Fixnum (Numeric) [ 31] awesome_inspect(*options) Fixnum (Kernel) [ 32] awesome_print(object, *options) Fixnum (Kernel) [ 33] between?(arg1, arg2) Fixnum (Comparable) [ 34] ceil() Fixnum (Integer) [ 35] chr(*arg1) Fixnum (Integer) [ 36] class() Fixnum (Kernel) [ 37] clone() Fixnum (Kernel) [ 38] coerce(arg1) Fixnum (Numeric) [ 39] conj() Fixnum (Numeric) [ 40] conjugate() Fixnum (Numeric) [ 41] define_singleton_method(*arg1) Fixnum (Kernel) [ 42] denominator() Fixnum (Integer) [ 43] display(*arg1) Fixnum (Kernel) [ 44] div(arg1) Fixnum [ 45] divmod(arg1) Fixnum [ 46] downto(arg1) Fixnum (Integer) [ 47] dup() Fixnum (Kernel) [ 48] enum_for(*arg1) Fixnum (Kernel) [ 49] eql?(arg1) Fixnum (Numeric) [ 50] equal?(arg1) Fixnum (BasicObject) [ 51] even?() Fixnum [ 52] extend(*arg1) Fixnum (Kernel) [ 53] fdiv(arg1) Fixnum [ 54] floor() Fixnum (Integer) [ 55] freeze() Fixnum (Kernel) [ 56] frozen?() Fixnum (Kernel) [ 57] gcd(arg1) Fixnum (Integer) [ 58] gcdlcm(arg1) Fixnum (Integer) [ 59] hash() Fixnum (Kernel) [ 60] i() Fixnum (Numeric) [ 61] imag() Fixnum (Numeric) [ 62] imaginary() Fixnum (Numeric) [ 63] initialize_clone(arg1) Fixnum (Kernel) [ 64] initialize_dup(arg1) Fixnum (Kernel) [ 65] inspect() Fixnum (Kernel) [ 66] instance_eval(*arg1) Fixnum (BasicObject) [ 67] instance_exec(*arg1) Fixnum (BasicObject) [ 68] instance_of?(arg1) Fixnum (Kernel) [ 69] instance_variable_defined?(arg1) Fixnum (Kernel) [ 70] instance_variable_get(arg1) Fixnum (Kernel) [ 71] instance_variable_set(arg1, arg2) Fixnum (Kernel) [ 72] instance_variables() Fixnum (Kernel) [ 73] integer?() Fixnum (Integer) [ 74] is_a?(arg1) Fixnum (Kernel) [ 75] kind_of?(arg1) Fixnum (Kernel) [ 76] lcm(arg1) Fixnum (Integer) [ 77] magnitude() Fixnum [ 78] method(arg1) Fixnum (Kernel) [ 79] methods(*args) Fixnum (Object) [ 80] modulo(arg1) Fixnum [ 81] next() Fixnum (Integer) [ 82] nil?() Fixnum (Kernel) [ 83] nonzero?() Fixnum (Numeric) [ 84] numerator() Fixnum (Integer) [ 85] object_id() Fixnum (Kernel) [ 86] odd?() Fixnum [ 87] ord() Fixnum (Integer) [ 88] phase() Fixnum (Numeric) [ 89] polar() Fixnum (Numeric) [ 90] pred() Fixnum (Integer) [ 91] private_methods(*args) Fixnum (Object) [ 92] protected_methods(*args) Fixnum (Object) [ 93] public_method(arg1) Fixnum (Kernel) [ 94] public_methods(*args) Fixnum (Object) [ 95] public_send(*arg1) Fixnum (Kernel) [ 96] quo(arg1) Fixnum (Numeric) [ 97] rationalize(*arg1) Fixnum (Integer) [ 98] real() Fixnum (Numeric) [ 99] real?() Fixnum (Numeric) [100] rect() Fixnum (Numeric) [101] rectangular() Fixnum (Numeric) [102] remainder(arg1) Fixnum (Numeric) [103] respond_to?(*arg1) Fixnum (Kernel) [104] respond_to_missing?(arg1, arg2) Fixnum (Kernel) [105] round(*arg1) Fixnum (Integer) [106] send(*arg1) Fixnum (Kernel) [107] singleton_class() Fixnum (Kernel) [108] singleton_method_added(arg1) Fixnum (Numeric) [109] singleton_methods(*args) Fixnum (Object) [110] size() Fixnum [111] step(*arg1) Fixnum (Numeric) [112] succ() Fixnum [113] taint() Fixnum (Kernel) [114] tainted?() Fixnum (Kernel) [115] tap() Fixnum (Kernel) [116] times() Fixnum (Integer) [117] to_c() Fixnum (Numeric) [118] to_enum(*arg1) Fixnum (Kernel) [119] to_f() Fixnum [120] to_i() Fixnum (Integer) [121] to_int() Fixnum (Integer) [122] to_r() Fixnum (Integer) [123] to_s(*arg1) Fixnum [124] truncate() Fixnum (Integer) [125] trust() Fixnum (Kernel) [126] untaint() Fixnum (Kernel) [127] untrust() Fixnum (Kernel) [128] untrusted?() Fixnum (Kernel) [129] upto(arg1) Fixnum (Integer) [130] zero?() Fixnum [131] |(arg1) Fixnum [132] ~() Fixnum ] => 0
排除从Objectinheritance的方法可能也很有用。
(Fixnum.public_instance_methods - Object.public_instance_methods).sort => [:%, :&, :*, :**, :+, :+@, :-, :-@, :/, :<, :<<, :<=, :>, :>=, :>>, :[], :^, :abs, :abs2, :angle, :arg, :between?, :ceil, :chr, :coerce, :conj, :conjugate, :denominator, :div, :divmod, :downto, :even?, :fdiv, :floor, :gcd, :gcdlcm, :i, :imag, :imaginary, :integer?, :lcm, :magnitude, :modulo, :next, :nonzero?, :numerator, :odd?, :ord, :phase, :polar, :pred, :quo, :rationalize, :real, :real?, :rect, :rectangular, :remainder, :round, :singleton_method_added, :size, :step, :succ, :times, :to_c, :to_f, :to_i, :to_int, :to_r, :truncate, :upto, :zero?, :|, :~]
或者更具可读性：
(Fixnum.public_instance_methods - Object.public_instance_methods).sort.join(" ") => "% & * ** + +@ - -@ / < << <= > >= >> [] ^ abs abs2 angle arg between? ceil chr coerce conj conjugate denominator div divmod downto even? fdiv floor gcd gcdlcm i imag imaginary integer? lcm magnitude modulo next nonzero? numerator odd? ord phase polar pred quo rationalize real real? rect rectangular remainder round singleton_method_added size step succ times to_c to_f to_i to_int to_r truncate upto zero? | ~"
几乎开箱即用的简单方法是：
require 'yaml' y (5.methods - Object.methods).sort
为方便起见，您还可以创建包含这些方法的.irbrc文件：
require 'yaml' def yppo(obj) y((obj.methods - Object.methods).sort) end def yppc(obj) y((obj.methods - Class.methods).sort) end
然后就像yppo(5)一样简单yppo(5) 。
我通常使用的另一个技巧是grep方法：
y (5.methods - Object.methods).sort.grep /to_/
事实上，你回答了自己的问题：
require 'pp' pp 5.methods [:to_s, :-@, :+, :-, :*, :/, :div, :%, :modulo, :divmod, :fdiv, :**, :abs, :magnitude, :==, :===, :<=>, etc
您好，这是一个简单的答案
5.methods.each {|x| px}
现在解释。 “5”是“数字”，可以是任何其他Interger ……“。方法”这将调用适用于数字的所有方法的列表……“.each {| x | px}“这将在列表中打印所有方法。
我希望这有帮助。