Arrays 我将一个数组传递给我编写的ruby方法，但是ruby看到一个fixnum？

各位，我是一个超级Ruby n00b，在让我的第一个Ruby程序工作时遇到了问题。我在堆栈溢出上发现了Q和A，它们与我遇到的问题密切相关，但无论我做什么尝试，我都无法摆脱这个错误

我写了两门课，结帐和注册。下面是完整的注册类：

<code>
load 'Register.rb'

class Checkout
    def initialize
        @register = Register.new
        @itemCount = Hash['CH1', 0, 'AP1', 0, 'CF1', 0, 'MK1', 0]
        @@inventory = Hash['CH1', 3.11, 'AP1', 6.00, 'CF1', 11.23, 'MK1', 4.75]
        @@discount = Hash['CF1', ['BOGO', '@itemCount["CF1"]%2==0', -11.23, '@register.findLast("CF1")'], 'AP1', ['APPL', '@itemCount["AP1"]>=3', -1.50, '@itemCount["AP1"]==3 ? @register.findAll("AP1") : @register.findLast("AP1")'], 'MK1', ['CHMK', '@itemCount["MK1"]==1 && @itemCount["CH1"]==1', -4.75, '@register.findAll("MK1")']]   
    end

    def scan(item)
        #get price of item from inventory
        price = @@inventory[item]
        #add item and price to register
        @register.ringUp(item, price)
        @itemCount[item]+=1
        #find and apply any applicable special
        discountCheck = @@discount[item]

        unless discountCheck == nil
            nameOfDiscount = @@discount[item][0]
            discountCondition = @@discount[item][1]
            moneyOff = @@discount[item][2]
            howToGetItemIndex = @@discount[item][3]
            if(eval(discountCondition))
                ind = eval(howToGetItemIndex)
                if(ind.class == "Array")
                    @register.applyDiscount(ind, moneyOff, nameOfDiscount)
                else #it's a Fixnum so we want to put it in an array first
                    indArray = [ind]
                    @register.applyDiscount(indArray, moneyOff, nameOfDiscount)    
                end
            end
        end
    end
end
</code>

<code>
class Register
    def initialize
        @itemsInOrderOfScan = Array.new
        @itemInfoInOrderOfScan = Array.new
    end

    def ringUp(item, price)
        @itemsInOrderOfScan.push(item)
        @itemInfoInOrderOfScan.push(['', price])
    end

    def applyDiscount(indices, moneyOff, nameOfDiscount)
        for i in 0..indices.length-1
            ind = indices[i]
            newInd = ind + 1
            @itemsInOrderOfScan.insert(newInd, '')
            @itemInfoInOrderOfScan.insert(newInd, [nameOfDiscount, moneyOff])
        end
    end

    def findLast(item)
        arr = Array.new
        ind = @itemsInOrderOfScan.rindex(item)
        arr.push(ind)
        arr
    end

    def findAll(item)
        indexOfFirstInstanceOfItem = @itemsInOrderOfScan.index(item)
        arr = findLast(item)
        indexOfLastInstanceOfItem = arr.at(0)

        for i in indexOfFirstInstanceOfItem..indexOfLastInstanceOfItem
            if(@itemsInOrderOfScan.at(i) == item)
                arr.push(i)          
            end
        end
        arr
    end

    def printReceipt
        puts "Item\t\t\tPrice"
        puts "----\t\t\t-----"
        total = 0
        for i in 0..@itemsInOrderOfScan.length-1
            currentItem = @itemsInOrderOfScan.at(i)
            currentDiscountName = @itemInfoInOrderOfScan.at(i)[0]
            currentPrice = @itemInfoInOrderOfScan.at(i)[1]
            total += currentPrice
            puts "#{currentItem}\t#{currentDiscountName}\t\t#{currentPrice}"
        end
        puts "-----------------------------------\n\t\t\t#{total}"
    end
end
</code>

下面是注册类：

<code>
load 'Register.rb'

class Checkout
    def initialize
        @register = Register.new
        @itemCount = Hash['CH1', 0, 'AP1', 0, 'CF1', 0, 'MK1', 0]
        @@inventory = Hash['CH1', 3.11, 'AP1', 6.00, 'CF1', 11.23, 'MK1', 4.75]
        @@discount = Hash['CF1', ['BOGO', '@itemCount["CF1"]%2==0', -11.23, '@register.findLast("CF1")'], 'AP1', ['APPL', '@itemCount["AP1"]>=3', -1.50, '@itemCount["AP1"]==3 ? @register.findAll("AP1") : @register.findLast("AP1")'], 'MK1', ['CHMK', '@itemCount["MK1"]==1 && @itemCount["CH1"]==1', -4.75, '@register.findAll("MK1")']]   
    end

    def scan(item)
        #get price of item from inventory
        price = @@inventory[item]
        #add item and price to register
        @register.ringUp(item, price)
        @itemCount[item]+=1
        #find and apply any applicable special
        discountCheck = @@discount[item]

        unless discountCheck == nil
            nameOfDiscount = @@discount[item][0]
            discountCondition = @@discount[item][1]
            moneyOff = @@discount[item][2]
            howToGetItemIndex = @@discount[item][3]
            if(eval(discountCondition))
                ind = eval(howToGetItemIndex)
                if(ind.class == "Array")
                    @register.applyDiscount(ind, moneyOff, nameOfDiscount)
                else #it's a Fixnum so we want to put it in an array first
                    indArray = [ind]
                    @register.applyDiscount(indArray, moneyOff, nameOfDiscount)    
                end
            end
        end
    end
end
</code>

<code>
class Register
    def initialize
        @itemsInOrderOfScan = Array.new
        @itemInfoInOrderOfScan = Array.new
    end

    def ringUp(item, price)
        @itemsInOrderOfScan.push(item)
        @itemInfoInOrderOfScan.push(['', price])
    end

    def applyDiscount(indices, moneyOff, nameOfDiscount)
        for i in 0..indices.length-1
            ind = indices[i]
            newInd = ind + 1
            @itemsInOrderOfScan.insert(newInd, '')
            @itemInfoInOrderOfScan.insert(newInd, [nameOfDiscount, moneyOff])
        end
    end

    def findLast(item)
        arr = Array.new
        ind = @itemsInOrderOfScan.rindex(item)
        arr.push(ind)
        arr
    end

    def findAll(item)
        indexOfFirstInstanceOfItem = @itemsInOrderOfScan.index(item)
        arr = findLast(item)
        indexOfLastInstanceOfItem = arr.at(0)

        for i in indexOfFirstInstanceOfItem..indexOfLastInstanceOfItem
            if(@itemsInOrderOfScan.at(i) == item)
                arr.push(i)          
            end
        end
        arr
    end

    def printReceipt
        puts "Item\t\t\tPrice"
        puts "----\t\t\t-----"
        total = 0
        for i in 0..@itemsInOrderOfScan.length-1
            currentItem = @itemsInOrderOfScan.at(i)
            currentDiscountName = @itemInfoInOrderOfScan.at(i)[0]
            currentPrice = @itemInfoInOrderOfScan.at(i)[1]
            total += currentPrice
            puts "#{currentItem}\t#{currentDiscountName}\t\t#{currentPrice}"
        end
        puts "-----------------------------------\n\t\t\t#{total}"
    end
end
</code>

当我尝试运行这些类时，这些类的工作方式如下：我为Checkout提供各种项目，这两个类一起创建一个收据，显示购买了什么以及在调用printReceive方法时可以应用的任何折扣

我用于调试的测试如下所示：

<code>
load 'Checkout.rb'

basket = ['CH1', 'AP1', 'AP1', 'AP1', 'MK1']
co = Checkout.new
for i in 0..basket.length
    puts basket.at(i)
    co.scan(basket[i])
end

co.register.print()
</code>

<code>
    CH1
    AP1
    AP1
    AP1
    Register.rb:16:in `+': no implicit conversion of Fixnum into Array (TypeError)
            from Register.rb:16:in `block in applyDiscount'
            from Register.rb:14:in `each'
            from Register.rb:14:in `applyDiscount'
            from Checkout.rb:33:in `scan'
            from main.rb:9:in `block in <main>'
            from main.rb:7:in `each'
            from main.rb:7:in `<main>'
</code>

运行测试时的输出如下所示：

<code>
load 'Checkout.rb'

basket = ['CH1', 'AP1', 'AP1', 'AP1', 'MK1']
co = Checkout.new
for i in 0..basket.length
    puts basket.at(i)
    co.scan(basket[i])
end

co.register.print()
</code>

<code>
    CH1
    AP1
    AP1
    AP1
    Register.rb:16:in `+': no implicit conversion of Fixnum into Array (TypeError)
            from Register.rb:16:in `block in applyDiscount'
            from Register.rb:14:in `each'
            from Register.rb:14:in `applyDiscount'
            from Checkout.rb:33:in `scan'
            from main.rb:9:in `block in <main>'
            from main.rb:7:in `each'
            from main.rb:7:in `<main>'
</code>

CH1
AP1
AP1
AP1
Register.rb:16:in`+'：没有将Fixnum隐式转换为数组（TypeError）
来自Register.rb:16:in'block in applyDiscount'
来自Register.rb:14:in'each'
来自Register.rb:14:in'applyDiscount'
从结帐处。rb:33:in'scan'
从main.rb:9:in'block in'
从main.rb:7:in'each'
从main.rb:7:in`'

请帮忙

---

提前谢谢。

您需要在4个位置进行修复

在

Checkout.rb

中，如果（ind.class==“Array”）比较错误，则

将

使用
if（ind.class.to=“Array”）
或更好地使用
if（ind.instance\u of？Array）

在您的

main.rb

中，使用

表示0…basket.length中的i，而不是
表示0…basket.length中的i，因为
1..2
=>[1,2]但是
1…3
=>[1,2]

在

Checkout.rb

中，课后第一行应该是

attr\u accessor:register

，因为您在

main.rb中访问register

在

main.rb

中，

co.register.printReceive

而不是

co.register.print（）

main.rb：

load 'Checkout.rb'

basket = ['CH1', 'AP1', 'AP1', 'AP1', 'MK1']
co = Checkout.new
for i in 0...basket.length
    puts basket.at(i)
    co.scan(basket[i])
end
co.register.printReceipt

Checkout.rb：

load 'Register.rb'

class Checkout
    attr_accessor :register
    def initialize
        @register = Register.new
        @itemCount = Hash['CH1', 0, 'AP1', 0, 'CF1', 0, 'MK1', 0]
        @@inventory = Hash['CH1', 3.11, 'AP1', 6.00, 'CF1', 11.23, 'MK1', 4.75]
        @@discount = Hash['CF1', ['BOGO', '@itemCount["CF1"]%2==0', -11.23, '@register.findLast("CF1")'], 'AP1', ['APPL', '@itemCount["AP1"]>=3', -1.50, '@itemCount["AP1"]==3 ? @register.findAll("AP1") : @register.findLast("AP1")'], 'MK1', ['CHMK', '@itemCount["MK1"]==1 && @itemCount["CH1"]==1', -4.75, '@register.findAll("MK1")']]
    end

    def scan(item)
        #get price of item from inventory
        price = @@inventory[item]
        #add item and price to register
        @register.ringUp(item, price)
        p item
        p @itemCount[item]
        @itemCount[item]+=1
        #find and apply any applicable special
        discountCheck = @@discount[item]

        unless discountCheck == nil
            nameOfDiscount = @@discount[item][0]
            discountCondition = @@discount[item][1]
            moneyOff = @@discount[item][2]
            howToGetItemIndex = @@discount[item][3]
            if(eval(discountCondition))
                ind = eval(howToGetItemIndex)
                if(ind.class.to_s == "Array")
                    @register.applyDiscount(ind, moneyOff, nameOfDiscount)
                else #it's a Fixnum so we want to put it in an array first
                    indArray = [ind]
                    @register.applyDiscount(indArray, moneyOff, nameOfDiscount)
                end
            end
        end
    end
end

---

非常感谢你，阿克法里迪！你把那些虫子都除掉了。我真的很欣赏这双新鲜的眼睛。