blocks|key|1520553|text|使用Regexp.new：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1520554|if+goo+=~+Regexp.new(foo)+#+Evaluates+to+/0.0.0.0/|code-block|syntax|javascript|1520555|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Use Regexp.new:

<pre><code>if goo =~ Regexp.new(foo) # Evaluates to /0.0.0.0/
</code></pre>

blocks|key|1735698|text|插值法可能是一个起点，但是有什么好的理由不能使用更传统的表达式--+Regexp.escape(foo)："my+stuff+#{mysubstitutionvariable}"|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1735699|此外，您也可以只将!goo.match(foo).nil?与文字字符串一起使用。|1735700|entityMap^0|Y|I|1H|10|0|9|K|0^^$0|@$1|2|3|4|5|6|7|J|8|@$9|K|A|L|B|C]|$9|M|A|N|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|O|8|@$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|H|3|-4|5|6|7|R|8|@]|D|@]|E|$]]]|I|$]]

Probably <code>Regexp.escape(foo)</code> would be a starting point, but is there a good reason you can't use the more conventional expression-interpolation: <code>"my stuff #{mysubstitutionvariable}"</code>?

Also, you can just use <code>!goo.match(foo).nil?</code> with a literal string.

blocks|key|1735702|text|Regexp.compile(Regexp.escape(foo))|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1735703|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>Regexp.compile(Regexp.escape(foo))
</code></pre>

blocks|key|1735760|text|与字符串插入相同。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1735761|if+goo+=~+/#{Regexp.quote(foo)}/
#...|code-block|syntax|javascript|1735762|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Same as string insertion.

<pre><code>if goo =~ /#{Regexp.quote(foo)}/
#...
</code></pre>

blocks|key|1735793|text|foo+=+"0.0.0.0"
goo+=+"here+is+some+other+stuff+0.0.0.0"+

puts+"success!"+if+goo+=~+/#{foo}/|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1735794|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>foo = "0.0.0.0"
goo = "here is some other stuff 0.0.0.0" 

puts "success!" if goo =~ /#{foo}/
</code></pre>

blocks|key|1735866|text|请注意，Jon+L.'s+answer中的Regexp.quote很重要！|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1735867|if+goo+=~+/#{Regexp.quote(foo)}/|code-block|syntax|javascript|1735868|如果你只做“显而易见”的版本：|1735869|if+goo+=~+/#{foo}/|1735870|然后，匹配文本中的句号将被视为正则表达式通配符，并且"0.0.0.0"将匹配"0a0b0c0"。|1735871|另请注意，如果您真的只想检查子字符串匹配，您可以简单地这样做|1735872|if+goo.include?(foo)|1735873|它不需要额外的引号，也不需要担心特殊字符。|1735874|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/a/150115/211563|1|http://ruby-doc.org/core/Regexp.html#method-c-quote^0|L|C|4|F|0|L|C|1|0|0|0|0|Q|9|12|9|0|0|0|0^^$0|@$1|2|3|4|5|6|7|16|8|@$9|17|A|18|B|C]]|D|@$9|19|A|1A|1|1B]|$9|1C|A|1D|1|1E]]|E|$]]|$1|F|3|G|5|H|7|1F|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|1G|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|1H|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|1I|8|@$9|1J|A|1K|B|C]|$9|1L|A|1M|B|C]]|D|@]|E|$]]|$1|Q|3|R|5|6|7|1N|8|@]|D|@]|E|$]]|$1|S|3|T|5|H|7|1O|8|@]|D|@]|E|$I|J]]|$1|U|3|V|5|6|7|1P|8|@]|D|@]|E|$]]|$1|W|3|-4|5|6|7|1Q|8|@]|D|@]|E|$]]]|X|$Y|$5|Z|10|11|E|$12|13]]|14|$5|Z|10|11|E|$12|15]]]]

Note that the <a href="http://ruby-doc.org/core/Regexp.html#method-c-quote" rel="noreferrer"><code>Regexp.quote</code></a> in <a href="https://stackoverflow.com/a/150115/211563">Jon L.'s answer</a> is important!

<pre><code>if goo =~ /#{Regexp.quote(foo)}/
</code></pre>

If you just do the "obvious" version:

<pre><code>if goo =~ /#{foo}/
</code></pre>

then the periods in your match text are treated as regexp wildcards, and <code>"0.0.0.0"</code> will match <code>"0a0b0c0"</code>.

Note also that if you really just want to check for a substring match, you can simply do

<pre><code>if goo.include?(foo)
</code></pre>

which doesn't require an additional quoting or worrying about special characters.

blocks|key|1520858|text|这是一个有限但有用的其他答案：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1520859|我发现，如果我只在输入字符串上使用单引号，我可以很容易地插入到正则表达式中，而无需使用Regexp.quote或Regexp.escape：(+IP地址匹配)|1520860|IP_REGEX+=+'\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}'

my_str+=+"192.0.89.234+blahblah+text+1.2,+1.4"+#+get+the+first+ssh+key+
#+replace+the+ip,+for+demonstration
my_str.gsub!(/#{IP_REGEX}/,"192.0.2.0")+
puts+my_str+#+"192.0.2.0+blahblah+text+1.2,+1.4"|code-block|syntax|javascript|1520861|单引号仅解释\和\‘。|1520862|http://en.wikibooks.org/wiki/Ruby_Programming/Strings#Single_quotes|offset|length|1520863|当我需要多次使用正则表达式的相同长部分时，这对我很有帮助。不是通用的，但我相信符合问题的例子。|1520864|entityMap|0|LINK|mutability|MUTABLE|url^0|0|0|0|0|0|1V|0|0|0^^$0|@$1|2|3|4|5|6|7|X|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|Y|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|Z|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|10|8|@]|9|@]|A|$]]|$1|K|3|L|5|6|7|11|8|@]|9|@$M|12|N|13|1|14]]|A|$]]|$1|O|3|P|5|6|7|15|8|@]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|16|8|@]|9|@]|A|$]]]|R|$S|$5|T|U|V|A|$W|L]]]]

Here's a limited but useful other answer:

I discovered I that I can easily insert into a regex without using Regexp.quote or Regexp.escape if I just used single quotes on my input string: (an IP address match)

<pre><code>IP_REGEX = '\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}'

my_str = "192.0.89.234 blahblah text 1.2, 1.4" # get the first ssh key 
# replace the ip, for demonstration
my_str.gsub!(/#{IP_REGEX}/,"192.0.2.0") 
puts my_str # "192.0.2.0 blahblah text 1.2, 1.4"
</code></pre>

single quotes only interpret \\ and \'.

<a href="http://en.wikibooks.org/wiki/Ruby_Programming/Strings#Single_quotes" rel="nofollow">http://en.wikibooks.org/wiki/Ruby_Programming/Strings#Single_quotes</a>

This helped me when i needed to use the same long portion of a regex several times. 
Not universal, but fits the question example, I believe.

I need to substitute the value of a string into my regular expression in Ruby. Is there an easy way to do this? For example:

<pre><code>foo = "0.0.0.0"
goo = "here is some other stuff 0.0.0.0" 
if goo =~ /value of foo here dynamically/
 puts "success!"
end
</code></pre>

Interpolating a string into a regex

我需要将字符串的值替换为Ruby中的正则表达式。有什么简单的方法可以做到这一点吗？例如：foo = "0.0.0.0"goo = "here is some other stuff 0.0.0.0" if goo =~ /value of foo here dynamically/  puts "success!"en...

问将字符串插入到正则表达式中
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