在Ruby中动态创建数组

weekly_sales = {}
puts 'Please enter a list of books'
book_list = gets.chomp
books = book_list.split(',')

books.each do |book|
  puts "Please input weekly sales of #{book} separated by a comma."
  weekly_sales[book] = gets.chomp.split(',') 
end

在ruby中,有一个哈希的概念,它是一个键/值对。在本例中,weekly_sales是散列,我们使用图书名称作为键,数组作为值。

我对您的代码做了一个小小的更改,而不是使用books.count.times来定义循环,然后使用计数器取消对数组元素的引用,这是迭代集合的一种更好的方法。

Ruby Docs->Array->push

无论如何,您需要一个更强大的数据结构。

weekly_sales 将是一个与 books 数组。这种方法的缺点是您必须自己维护这两个数组的并行性。

一个更好的解决方案是使用书名作为数组散列的键,正如一些答案所建议的那样。例如: weekly_sales['Fahrenheit 451']

一种更健壮的方法,你可能要考虑的是把每一本书的信息捆绑到一个包中。

books = [
    {
        'title' => 'Fahrenheit 451',
        'sales' => [1,2,3],
    },
    {
        'title' => 'Slaughterhouse-Five',
        'sales' => [123,456],
    },
]

puts books[1]['title']

另一个极端是创造一个合适的 Book 班级。

Struct OpenStruct

# Define the attributes that a Book will have.
Book = Struct.new(:title, :weekly_sales)
books = []

# Simulate some user input.
books_raw_input = "Fahrenheit 451,Slaughterhouse-Five\n"
sales_raw_input = ['1,2,3', '44,55,66,77']
books_raw_input.chomp.split(',').each do |t|
    ws = sales_raw_input.shift.split(",")
    # Create a new Book.
    books.push Book.new(t, ws)        
end

# Now each book is a handy bundle of information.
books.each do |b|
    puts b.title
    puts b.weekly_sales.join(', ')
end

您是否愿意以数组结束?这可能有用:

book_sales = books_array.collect do |book|
  puts "Please input weekly sales of #{books_array[0]} separated by a comma."
  gets.chomp.split(",").collect{ |s| s.to_i }
end

看看它,你可能更喜欢一个由书键入的散列。大概是这样的:

book_sales = books_array.inject({}) do |hash, book|
  puts "Please input weekly sales of #{books_array[0]} separated by a comma."
  weekly_sales = gets.chomp.split(",").collect{ |s| s.to_i }
  hash[book] = weekly_sales
end

此解决方案假定永远不会有重复的书名。我觉得这很安全,是吗?

input = "A list of words"
hash = {}
input.split(/\s+/).collect { |word| hash[word] = [] }

# Now do whatever with each entry
hash.each do |word,ary|
   ary << ...
end

result = "The Great Gatsby, Crime and Punishment, Dracula, Fahrenheit 451,
  Pride and Prejudice, Sense and Sensibility, Slaughterhouse-Five, 
  The Adventures of Huckleberry Finn".split(/,\s*/).map do |b|
    puts "Please input weekly sales of #{b} separated by a comma."
    gets.chomp.split(',') # .map { |e| e.to_i }
end
p result

如果希望将输入字符串转换为数字,请删除注释