Why "NoMethodError" occurs

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!

U passed “332” as a string so it was stored as a string. Take the
quotes off 332 or better, in ur init, say @duration=duration.to_i

Mike

that make sense
thanks