我有字符串 "111221" 并且想要匹配所有连续相等的整数集:["111", "22", "1"].
I have the string "111221" and want to match all sets of consecutive equal integers: ["111", "22", "1"].
我知道有一个特殊的正则表达式可以做到这一点,但我不记得了,而且我在谷歌上搜索很糟糕.
I know that there is a special regex thingy to do that but I can't remember and I'm terrible at Googling.
推荐答案在 Ruby 1.8.7+ 中使用正则表达式:
Using regex in Ruby 1.8.7+:
p s.scan(/((\d)\2*)/).map(&:first) #=> ["111", "22", "1"]这是有效的,因为 (\d) 捕获任何数字,然后 \2* 捕获该组(第二个左括号)匹配的零个或多个.作为 scan 的结果,需要外部 (…) 来捕获整个匹配项.最后,scan 单独返回:
This works because (\d) captures any digit, and then \2* captures zero-or-more of whatever that group (the second opening parenthesis) matched. The outer (…) is needed to capture the entire match as a result in scan. Finally, scan alone returns:
[["111", "1"], ["22", "2"], ["1", "1"]]...所以我们需要遍历并保留每个数组中的第一项.在 Ruby 1.8.6+ 中(为了方便,没有 Symbol#to_proc):
…so we need to run through and keep just the first item in each array. In Ruby 1.8.6+ (which doesn't have Symbol#to_proc for convenience):
p s.scan(/((\d)\2*)/).map{ |x| x.first } #=> ["111", "22", "1"]没有正则表达式,这是一个在 Ruby 1.9.2 中工作的有趣的(匹配任何字符):
With no Regex, here's a fun one (matching any char) that works in Ruby 1.9.2:
p s.chars.chunk{|c|c}.map{ |n,a| a.join } #=> ["111", "22", "1"]这是另一个即使在 Ruby 1.8.6 中也能工作的版本:
Here's another version that should work even in Ruby 1.8.6:
p s.scan(/./).inject([]){|a,c| (a.last && a.last[0]==c[0] ? a.last : a)<<c; a } # => ["111", "22", "1"]更多推荐
匹配字符串中连续字符的序列
发布评论