ruby的类-继承方法定义类变量与实例变量

感性的认识了一下ruby的类

class Song
#类变量
@@plays = 0
#构造函数
def initialize(name,artist,duration)
#实例变量
@name = name
@artist = artist
@duration = duration
end
def to_s
"Song: #@name--#@artist (#@duration) plays:#@@plays"
end
end
#类继承
class KaraokeSong < Song
#类方法
def self.getType
"KaraokeSongType"
end

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

#重写
def to_s
super + " duration:#@duration"
end
#protected方法
protected
def nono

end
#private方法
private
def noop
"noop"
end
end

song = KaraokeSong.new("My Way", "Sinatra", 100 , "The Way....")
puts(song.to_s)
puts(KaraokeSong.getType)