Ruby regex that does not match if there are keywords that you don’t want included in the string

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Abstract

Hello everyone it’s me candle. In this time I would like to create a regular expression that does not pass if keywords that I do not want included in the string match.

This is such case like this. For example, the regex matches these words “Bitcoin” and “Bitcoin ~” but doesn’t match “BitcoinCash” and “Bitcoin Cash”.

○ Bitcoin
○ Bitcoin Core
× BitcoinCash
× Bitcoin Cash

Condition

Nothing

Write the regex

This is a regex that does not match if there are keywords that you do not want included in the string.

 /Keyword to include(?!Keywords you do not want included)/

For example, if you want to match “Bitcoin” and “Bitcoin ~” and exclude “Bitcoin Cash” and “Bitcoin Cash”, it looks like this. |OR and \sspace symbols are mixed.

reg = /Bitcoin(?!Cash|\sCash)/

This is the sample code.

name1 = "Bitcoin"
name2 = "Bitcoin Core"
name3 = "BitcoinCash"
name4 = "Bitcoin Cash"

reg = /Bitcoin(?!Cash|\sCash)/

if name1 =~ reg
  p name1
end

if name2 =~ reg
  p name2
end

if name3 =~ reg
  p name3
end

if name4 =~ reg
  p name4
end

Conclusion

I think that it is really easy once you know a regular expression, but it will be quite hard before you figure it out.