在一行中打印多个数组

I'm trying to print several arrays on one line. The first line is ok but the loop breaks down after that. I've tried going over it serveral times but no cigar. Here's the code:

我正在尝试在一行上打印几个数组。第一行是正常的，但循环在此之后崩溃。我已经尝试了几次，但没有雪茄。这是代码：

chapter_num = ['Chapter 1', 'Chapter 2', 'Chapter 3']
chapter_title = ['Numbers', 'Letters', 'Variables']
chapter_page = ['page 1', 'page 72', 'page 118']

#Prints chapter number
chapter_num.each do |num|
    print (num.ljust 0)

    #Prints title
    chapter_title.each do |title|
            print (title.center 14)

            #Prints page number
            chapter_page.each do |page|
                    puts (page.rjust 40)
            end
    end
end

When I run the above code it looks like this:

当我运行上面的代码时，它看起来像这样：

Chapter 1   Numbers                                      page 1
                             page 72
                            page 118
   Letters                                      page 1
                             page 72
                            page 118
  Variables                                     page 1
                             page 72
                            page 118
Chapter 2   Numbers                                      page 1
                             page 72
                            page 118
   Letters                                      page 1
                             page 72
                            page 118
  Variables                                     page 1
                             page 72
                            page 118
Chapter 3   Numbers                                      page 1
                             page 72
                            page 118
  Letters                                      page 1
                             page 72
                            page 118
Variables                                     page 1
                             page 72
                            page 118

It's suppose to look like this:

它假设看起来像这样：

Chapter 1   Numbers                                      page 1
Chapter 2   Letters                                     page 72
Chapter 3  Variables                                   page 118

2 个解决方案

#1

You could use the Array::zip method here:

你可以在这里使用Array :: zip方法：

chapter_num = ['Chapter 1', 'Chapter 2', 'Chapter 3']
chapter_title = ['Numbers', 'Letters', 'Variables']
chapter_page = ['page 1', 'page 72', 'page 118']

arr = chapter_num.zip(chapter_title, chapter_page)
arr.each { |el| puts "#{el[0].ljust 0} #{el[1].center 14} #{el[2].rjust 40}" }

#=> Chapter 1    Numbers                                       page 1
#=> Chapter 2    Letters                                      page 72
#=> Chapter 3   Variables                                    page 118

And--since Array::zip takes an optional block--you could do it in one line:

并且 - 由于Array :: zip采用可选块 - 您可以在一行中执行：

chapter_num.zip(chapter_title, chapter_page).each { |el| puts "#{el[0].ljust 0} #{el[1].center 14} #{el[2].rjust 40}" }

#2

In your code you have three nested loops which is the reason for getting the output you are getting. You only need to have one loop for printing the i-th element of each of your arrays like this:

在你的代码中，你有三个嵌套循环，这是获得你得到的输出的原因。你只需要有一个循环来打印每个数组的第i个元素，如下所示：

chapter_num = ['Chapter 1', 'Chapter 2', 'Chapter 3']
chapter_title = ['Numbers', 'Letters', 'Variables']
chapter_page = ['page 1', 'page 72', 'page 118']

#Prints chapter number
(0..chapter_num.length-1).each do |i|
  puts "#{chapter_num[i].ljust 0} #{chapter_title[i].center 14} #{chapter_page[i].rjust 40}"
end

which prints out:

打印出来：

Chapter 1    Numbers                                       page 1
Chapter 2    Letters                                      page 72
Chapter 3   Variables                                    page 118

#1