--- undef_method(name)

    󥹥󥹤Ф name Ȥ᥽åɤƤӽФȤػ
    ޤ⤷ꤷ᥽åɤƤʤȤˤ㳰
    NameError ȯޤ

    undef Ȥΰ㤤ϡ᥽å̾ʸޤ
    Symbol Ϳ롢᥽åǤѤǤ롢Ǥ

    ޤ remove_method Ȥϥѡ饹Ѿ
    뤫ɤǶ̤ޤʲεư򻲾ȤƤ

      class A
        def ok() puts 'A' end
      end
      class B < A
        def ok() puts 'B' end
      end

      B.new.ok   # => B

      # undef_method ξϥѡ饹Ʊ̾Υ᥽åɤäƤ
      # θƤӽФϥ顼ˤʤ
      class B
        undef_method :ok
      end
      B.new.ok   # => NameError

      # remove_method ξϥѡ饹Ʊ̾Υ᥽åɤ
      # 줬ƤФ
      class B
        remove_method :ok
      end
      B.new.ok   # => A

    self ֤ޤ

