Ruby如何检测字符串中的回车？

Question

我正在遍历具有多个回车符的大字符串。我希望我的逻辑每次发现回车符时都要执行一些操作（在回车符之前创建一个具有所有字符串内容的新ActiveRecord实例）。

Answer 1

def doit(str)
  start_idx = 0
  while i = str.index("\n", start_idx)
    action str[0..i-1]
    start_idx = i+1
  end
end

def action(str)
  puts "This is what I've read: #{str}"
end

doit("Three blind mice,\nsee how they run.\nThey all ran after the farmer's wife\n")
  # This is what I've read: Three blind mice,
  # This is what I've read: Three blind mice,
  # see how they run.
  # This is what I've read: Three blind mice,
  # see how they run.
  # They all ran after the farmer's wife

请参见String#index。

如果只希望传递自上一个换行符以来的字符串部分，请更改该行：

action str[0..i-1]

至：

action str[start_idx..i-1]