Question

files = ["message_21.txt", "message_10.txt", "message_27.txt", "message_22.txt", "message_23.txt", "message_15.txt", "message_4.txt", "message_16.txt", "message_24.txt", "message_13.txt", "message_1.txt", "message_3.txt", "message_17.txt", "message_12.txt", "message_2.txt", "message_19.txt", "message_18.txt", "message_14.txt", "message_25.txt", "message_9.txt", "message_8.txt", "message_5.txt", "message_26.txt", "message_11.txt", "message_7.txt", "message_20.txt", "message_6.txt", "message_28.txt"]

files.each do |f|
file = File.new(PATH + "/" + f, "r")
        while (line = file.gets)
         @found=true if line =~ /You purchased/
         next unless @found
         puts line
         exit if line =~ /Order for/
    end
    file.close
end

如果message_4.txt包含'您购买'且'订单'字词完全退出循环。所以我无法获得包含这些术语的其他文件。我不知道我做了什么错误。

Answer 1

一旦达到'订购'，您是否试图突破while循环？因为'退出'不是你想要的。试试'休息'吧。此外，您还需要为每个文件重置@found变量。

files = ["message_21.txt", "message_10.txt", "message_27.txt", "message_22.txt", "message_23.txt", "message_15.txt", "message_4.txt", "message_16.txt", "message_24.txt", "message_13.txt", "message_1.txt", "message_3.txt", "message_17.txt", "message_12.txt", "message_2.txt", "message_19.txt", "message_18.txt", "message_14.txt", "message_25.txt", "message_9.txt", "message_8.txt", "message_5.txt", "message_26.txt", "message_11.txt", "message_7.txt", "message_20.txt", "message_6.txt", "message_28.txt"]

files.each do |f|
  @found = false
  file = File.new(PATH + "/" + f, "r")
  while (line = file.gets)
    @found=true if line =~ /You purchased/
    # below skips to start of next run of while loop
    next unless @found 
    puts line
    # below breaks out of while loop
    break if line =~ /Order for/ 
  end
  file.close
end

看看这个http://www.tutorialspoint.com/ruby/ruby_loops.htm - 尤其是“下一个”和“休息”的解释。

Answer 2

exit退出整个程序，而不仅仅是循环。您需要break，而不是exit来停止循环。

您还可以利用File.open接受一个块，该块会在块返回时为您关闭文件。

除非您有意存储至少在一个文件中找到@found行至少一次，否则也不需要You purchased。

最后，你应该修复你的缩进，每个级别使用两个空格，这是Ruby社区中公认的标准。

files = [...]

files.each do |f|
  File.open(PATH + "/" + f, "r") do |file|
    while line = file.gets
      next unless line =~ /You purchased/
      puts line
      break if line =~ /Order for/
    end
  end
end

红宝石循环过早退出

2 个答案: