From: gao bo <gaob06@...>
Date: 2007-05-19T11:07:17+09:00
Subject: Why "NoMethodError" occurs

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hi, everyone
today i typed the code below in my IDE

class Song
  attr_reader :name, :artist, :duration
  attr_writer :duration

  def initialize(name, artist, duration)
    @name = name
    @artist = artist
    @duration = duration
  end

  def durationInMinutes
    @duration/60.0
  end

  def durationInMinutes=(value)
    @duration = (value * 60).to_i
  end
end

class Song
  def to_s
    "song: #{@name}--#{@artist}  (#{@duration})"
  end
end

aSong = Song.new("hello", "zhutou","332")

puts aSong.to_s
puts aSong.durationInMinutes

And i tried to run it, but the error occured:

song: hello--zhutou  (332)
song.rb:12:in `durationInMinutes': undefined method `/' for "332":String
(NoMethodError)
 from song.rb:29

Why?

Thanks!

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