Question

写一个理性的类，我收到一个错误，虽然我看不出我的代码有什么问题。这是课堂和相关方法：

class Rational
    attr_reader :numerator, :denominator     

    def initialize(numerator=1,denominator=1)
        @numerator = numerator
        @denominator = denominator
        reduce
    end

    class << self   

        def lcd(r1,r2)
               ...
                       ...
        end

        def add(r1,r2)
            if r1.denominator != r2.denominator
                lcd(r1,r2)
            end
            Rational r = Rational.new(r1.numerator + r2.numerator, r1.denominator)
            r1.reduce
            r2.reduce
            return r
        end


end
r = Rational.new
r2 = Rational.new(1,3)
r3 = Rational.new(1,4)
r = Rational.add(r2,r3)

我得到的错误：

rational.rb:53:in `add': undefined method `Rational' for Rational:Class (NoMethodError)

提前感谢！

Answer 1

你是来自Java吗？在ruby中，您不必在声明中指定变量类型

Rational r = Rational.new(r1.numerator + r2.numerator, r1.denominator)

应该是

r = Rational.new(r1.numerator + r2.numerator, r1.denominator)

Answer 2

在ruby中，您不会声明类型：

Rational r = ...

错误！ Ruby解释为方法使用参数r。

调用Rational（）

RUBY没有类方法的方法错误

2 个答案: