Question

如何在Ruby中的字符串的两个字符串标记之间返回字符串？

例如我有：

input_string
str1_markerstring
str2_markerstring

想做类似的事情：

input_string.string_between_markers(str1_markerstring, str2_markerString)

示例文字：

1.9.3-p0 :020 >   s
 => "Charges for the period 2012-01-28 00:00:00 to 2012-02-27 23:59:59:<br>\nAny Network Cap remaining: $366.550<br>International Cap remaining: $0.000"
1.9.3-p0 :021 > str1_markerstring
 => "Charges for the period"
1.9.3-p0 :022 > str2_markerstring
 => "Any Network Cap"
1.9.3-p0 :023 > s[/#{str1_markerstring}(.*?)#{str2_markerstring}/, 1]
 => nil  # IE DIDN'T WORK IN THIS CASE

Answer 1

input_string = "blahblahblahSTARTfoofoofooENDwowowowowo"
str1_markerstring = "START"
str2_markerstring = "END"

input_string[/#{str1_markerstring}(.*?)#{str2_markerstring}/m, 1]
#=> "foofoofoo"

或将其放入方法中：

class String
  def string_between_markers marker1, marker2
    self[/#{Regexp.escape(marker1)}(.*?)#{Regexp.escape(marker2)}/m, 1]
  end
end

"blahblahblahSTARTfoofoofooENDwowowowowo".string_between_markers("START", "END")
#=> "foofoofoo"

Answer 2

只需将其拆分两次，然后在标记之间获取字符串：

input_string.split("str1_markerstring").last.split("str2_markerstring").first

Answer 3

这里有一些替代方法可以做你想做的事情，这就是我要做的事情：

s = "Charges for the period 2012-01-28 00:00:00 to 2012-02-27 23:59:59:<br>\nAny Network Cap remaining: $366.550<br>International Cap remaining: $0.000"  # => "Charges for the period 2012-01-28 00:00:00 to 2012-02-27 23:59:59:<br>\nAny Network Cap remaining: $366.550<br>International Cap remaining: $0.000"

dt1, dt2 = /period (\S+ \S+) to (\S+ \S+):/.match(s).captures  # => ["2012-01-28 00:00:00", "2012-02-27 23:59:59"]
dt1                                                            # => "2012-01-28 00:00:00"
dt2                                                            # => "2012-02-27 23:59:59"

这是使用＆＃34; period＆＃34;和＆＃34;到＆＃34;和尾随＆＃34;：＆＃34;标记要搜索的范围的开头和结尾，并抓取表示每个日期时间戳中日期和时间的非空白字符。

或者，使用＆＃34; named-captures＆＃34;预定义变量：

/period (?<dt1>\S+ \S+) to (?<dt2>\S+ \S+):/ =~ s  # => 16
dt1                                                # => "2012-01-28 00:00:00"
dt2                                                # => "2012-02-27 23:59:59"

从那时起，如果要分解返回的值，可以将它们解析为日期：

require 'date'
d1 = DateTime.strptime(dt1, '%Y-%m-%d %H:%M:%S')  # => #<DateTime: 2012-01-28T00:00:00+00:00 ((2455955j,0s,0n),+0s,2299161j)>
d1.month                                          # => 1
d1.day                                            # => 28

或者您甚至可以使用子捕获：

matches = /period (?<dt1>(?<date1>\S+) (?<time1>\S+)) to (?<dt2>(?<date2>\S+) (?<time2>\S+)):/.match(s)
matches # => #<MatchData "period 2012-01-28 00:00:00 to 2012-02-27 23:59:59:" dt1:"2012-01-28 00:00:00" date1:"2012-01-28" time1:"00:00:00" dt2:"2012-02-27 23:59:59" date2:"2012-02-27" time2:"23:59:59">
matches['dt1']   # => "2012-01-28 00:00:00"
matches['date1'] # => "2012-01-28"
matches['time2'] # => "23:59:59"

这些都记录在the Regexp documentation。

中

如何在Ruby中的两个字符串之间返回字符串的子串？

3 个答案: