a crux about nil test in ruby code -

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i have crux in ruby code(excerpt this page):

#!/usr/bin/env ruby  class megagreeter   attr_accessor :names    #create object   def initialize(names = "world")      @names = names   end    # hi   def say_hi     if @names.nil?       puts "..."     elseif @names.respond_to?("each")       # @names list of kind,iterate!       @names.each |name|          puts "hello #{name}!"       end     else       puts "hello #{@names}!"     end   end    # bye   def say_bye     if @names.nil?       puts "..."     elseif @names.respond_to?("join")       puts "goodbye #{@names.join(",")}. come soon."     else       puts "goodbye #{@names}. come soon."     end   end end  if __file__ == $0   mg = megagreeter.new   mg.say_hi   mg.say_bye    # change name "zeke"   mg.names = "zeke"   mg.say_hi   mg.say_bye    # change name array of names   mg.names = ["albert", "brenda", "charles", "dave", "engelbert"]   mg.say_hi   mg.say_bye    # change nil   mg.names = nil   mg.say_hi   mg.say_bye  end

when run script ruby command, prints:

hello world! goodbye world. come soon. hello zeke! goodbye zeke. come soon. hello ["albert", "brenda", "charles", "dave", "engelbert"]! goodbye ["albert", "brenda", "charles", "dave", "engelbert"]. come soon. ... ri20min.rb:15:in `say_hi': undefined method `elseif' #<megagreeter:0x00000001a2d4a0 @names=nil> (nomethoderror)         ri20min.rb:54:in `<main>'

i want check whether variable nil.

if @names.nil?

but error frustrated me! seems nil object has not nil method! how can amend code run correctly.

there no elseif in ruby, there elsif.


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