ruby Ruby on Rails指南：主动支持核心扩展 - http://guides.rubyonrails.org/active_support_core_extensions.html

Posted 2021-05-16

require 'active_support'
require 'active_support/core_ext'

class Fixnum
  def one?
    self == 1
  end
end

depth = 1
p depth.one? # => true

# it will out rescue block message
begin
  depth = nil
  p depth.one?
rescue
  puts "undefined method `one?' for nil:NilClass (NoMethodError)"
end

# it will not excute block, returns nil
depth = nil
p depth.try { |x| x.one? }