编辑代码

#JSRUN引擎2.0，支持多达30种语言在线运行，全仿真在线交互输入输出。

class Animal
  def eat
    puts "Animal eats food."
  end
end

class Cat < Animal
    def eat
      puts "Cat eats fish."
     end
end

cat = Cat.new
animal = Animal.new

puts cat.eat  # Animal eats food.
puts cat.super.eat




# do not override - output: Person eats fruits. 
# override - output: Child eats fruits.

=begin
def make_person_eat(person)
  person.eat
end

make_person_eat(person)  # Output: "Person eats fruits."
make_person_eat(kid)     # Output: "Child eats fruits."

=end

=begin
class Kid < Student

  def initialize(name, gender,id, year)
    super(name, gender, id)
    @year = year
  end

# override
  def eat
    puts "Child eats fruits."
  end

end
=end