Question

我几天前就开始学习Ruby了，而且我很难确定为什么我会得到＆＃39;没有方法＆＃39;对于明确定义的几种方法的错误。我怀疑有一些关于Ruby如何在后端工作的重要信息，我错过了。这是类代码;它只是制作自定义类的基本练习：

class OrangeTree

def initialize
    @height = 1.0
    @age = 0
    @number_of_oranges = 0
end

def yearPasses
    @age = @age + 1
    @height = @height + 1.5
    if @age >= 50
        puts 'The orange tree has died'
        exit
    else
    if @age > 3
        @number_of_oranges = 10 + @age
    end
    puts 'A year passes.'
    puts 'Your tree is ' + @age.to_s + ' years old.'
    puts
end

def height
    puts 'The tree is now ' + @height.to_s + ' feet tall.'
    puts
end

def countOranges
    puts 'There are ' + @number_of_oranges.to_s + ' oranges in the tree.'
    puts
end

def pickOrange
    if @number_of_oranges > 0
        @number_of_oranges -= 1
        puts 'You ate an orange. YUM!'
    else
        puts 'There are no oranges left to pick.'
    end
end
end

这是执行代码：

tree = OrangeTree.new
puts 'You just bought an orange tree!'
x = 0
while x == 0
    puts 'What would you like to do?  Measure, Count Oranges, Pick Orange, Pass Year'
    action = gets.chomp
    if action.downcase == 'measure'
        tree.height
        puts
    else    
        if action.downcase == 'count oranges'
            tree.countOranges
            puts
        else
            if action.downcase == 'pick orange'
                tree.pickOrange
                puts
            else
                if action.downcase == 'pass year'
                    tree.yearPasses
                    puts
                else
                    puts 'Invalid selection.'
                    puts
                end
            end
        end
    end
end
end

方法pickOrange初始化，yearPasses全部工作（虽然由于某种原因，在yearPasses执行超过4次之后树上仍然有0个橙子）。真正的问题是height和countOranges方法，每个方法都返回“无法”方法＆＃39;错误。对于初学Ruby编码器来说，这个错误似乎相当普遍，但我找到的其他答案帖子似乎都没有适用于我的实例。在此先感谢您的帮助！

Answer 1

您在这里缺少end：

def yearPasses
    @age = @age + 1
    @height = @height + 1.5
    if @age >= 50
        puts 'The orange tree has died'
        exit
    else
    if @age > 3
        @number_of_oranges = 10 + @age
    end
    # << ------ MISSING END
    puts 'A year passes.'
    puts 'Your tree is ' + @age.to_s + ' years old.'
    puts
end

改为将else改为elsif。

def yearPasses
    @age = @age + 1
    @height = @height + 1.5
    if @age >= 50
        puts 'The orange tree has died'
        exit
    elsif @age > 3
        @number_of_oranges = 10 + @age
    end
    puts 'A year passes.'
    puts 'Your tree is ' + @age.to_s + ' years old.'
    puts
end

为什么我会得到未定义的方法（没有方法错误）＆＃39;？

1 个答案: