ruby-on-rails - 如何在 Ruby 中对字符串应用除法运算符？

Question

我正在尝试将除法运算符 / 添加到 String，它接受一个整数。

运算符应生成一个字符串数组。数组的大小是给定的整数，它的元素是原始字符串的子字符串，这样当按顺序连接时，会产生原始字符串。

如果字符串长度不能被整数整除，一些子串应该比其他的长(一个字符)。两个字符串的长度相差不得超过 1，任何较长的字符串都应出现在任何较短的字符串之前。

像这样:

"This is a relatively long string" / 7
# => ["This ", "is a ", "relat", "ively", " lon", "g st", "ring"]

我该如何开始？

Answer 1

你可以使用递归。

class String
  def /(n)
    return [self] if n==1
    m = (self.size.to_f/n).ceil
    [self[0...m]].concat(self[m..-1] / (n-1))
  end
end

str = "This would be a woefully short string had I not padded it out."

str / 7
  # => ["This woul", "d be a wo", "efully sh", "ort strin", "g had I n",
  #     "ot padded", " it out."] 


(str / 7).map(&:size)
  #=> [10, 10, 9, 9, 9, 9, 9]