Question

我想将数组转换为在两个不同位置具有两个不同分隔符的字符串。意思是：

array = [1,2,3,4]
after converting: separator 1: (":") separator 2: ("and")
string = "1:2:3: and 4"
OR
string = "1:2 and 3:4"

如何构建动态和短代码，让我将数组（任意长度）转换为字符串，允许我在不同的位置插入多个分隔符。

我目前的解决方案是凌乱和丑陋的：我在一个参数中使用了#join。

def oxford_comma(array)
 if array.length == 1
  result_at_1 = array.join
  return result_at_1
 elsif array.length == 2
  result_at_2 = array.join(" and ")
  return result_at_2
 elsif array.length == 3
  last = array.pop
  result = array.join(", ")
  last = ", and " + last
  result = result + last
 elsif array.length > 3
  last = array.pop
  result = array.join(", ")
  last = ", and " + last
  result = result + last
  return result
 end
end

有人可以帮我建立一个更好，更短，更抽象的方法吗？

Answer 1

您可以使用Enumerable#slice_after。

array.slice_after(1).map { |e| e.join ":" }.join(" and ") #=> "1 and 2:3:4"
array.slice_after(2).map { |e| e.join ":" }.join(" and ") #=> "1:2 and 3:4"
array.slice_after(3).map { |e| e.join ":" }.join(" and ") #=> "1:2:3 and 4"

Answer 2

如果您使用的是rails / activesupport，那么it's built-in：

[1,2,3,4].to_sentence # => "1, 2, 3, and 4"
[1,2].to_sentence # => "1 and 2"
[1,2,3,4].to_sentence(last_word_connector: ' and also ') # => "1, 2, 3 and also 4"

如果不这样做，请复制activesupport的实现，例如：）

注意：这不允许您将“和”放在序列的中间。不过，它非常适合牛津逗号。

Answer 3

pos = 2
[array[0...pos], array[pos..-1]].
  map { |e| e.join ':' }.
  join(' and ')
#⇒ "1:2 and 3:4"

Answer 4

<强>代码

def convert(arr, special_separators, default_separator, anchors={ :start=>'', :end=>'' })
  seps = (0..arr.size-2).map { |i| special_separators[i] || default_separator }
  [anchors.fetch(:start, ""), *[arr.first, *seps.zip(arr.drop(1)).map(&:join)],
    anchors.fetch(:end, "")].join
end

<强>实施例

arr = [1,2,3,4,5,6,7,8]
default_separator  = ':'

＃1

special_separators = { 1=>" and ", 3=>" or " }
convert(arr, special_separators, default_separator)
  #=> "1:2 and 3:4 or 5:6:7:8"

，其中

seps #=> [":", " and ", ":", " or ", ":", ":", ":"]

＃2

special_separators = { 1=>" and ", 3=>") or (", 5=>" and " }    
convert(arr, special_separators, default_separator, { start: "(", end: ")" })
  #=> "(1:2 and 3:4) or (5:6 and 7:8)"

，其中

seps #=> [":", " and ", ":", ") or (", ":", " and ", ":"]

如何在Ruby中的两个不同位置将数组转换为具有两个不同分隔符的字符串？

4 个答案: