How to exclude a string from my RegEx in Javascript?

Question

please excuse my title. Didn't know a better one. My problem. I have to find words. This words can have square brackets / parentheses around them or be in quotation marks. To find all words I use:

new RegEx('\\b' + arrWord + '\\b', 'g');

Now the problem. Some words have for example ["DN"]word or...ignore">,... in front of them. This words I don't want to find. I read something about RegEx exclude a string, but I can't get it to work. Does someone have an idea or can help? Or is it not possible to do something like that with RegEx in Javascript?

Answer 1

You can use something like this to do what's called in REGEX "negative lookahead":

\bword\b(?!...ignore)

Answer 2

This was kind of tricky because ["DN"] matches with "surrounded by quotations", so the final regex is a bit long. Here you have it with some examples, and the regex itself is:

(?<!\[\"DN\"\])(?<!\.\.\.ignore)(\[\w+\]|\(\w+\)|(\"\w+\")(?=(?<!\"DN\")))

Here you can see how it is composed:

• (?<!\[\"DN\"\]) asserts that the following string does not match ["DN"] .
• (?<.\.\.\.ignore) asserts that the following string does not match ...ignore .
• (\[\w+\]|\(\w+\)|(\"\w+\")(?=(?<!\"DN\"))) is composed by 3 OR conditions:
  • \[\w+\] matches if word is surrounded by brackets.
  • \(\w+\) matches if word is surrounded by parenthesis.
  • (\"\w+\")(?=(?<!\"DN\")) matches if word surrounded by quotations and is not "DN" .

I hope it helps!