I want a regular expression to match everything but two strings, STRING1 and STRING2.
^(?!STRING1|STRING2).*$ is close, but it does not match STRING1X, which should be matched, because STRING1X is not equal to STRING1 and not equal to STRING2.
^(?!STRING1|STRING2)$ doesn’t match anything.
>Solution :
^(?!STRING1$|STRING2$).*
Explanation:
^ asserts the start of the string.
(?!STRING1$|STRING2$) is a negative lookahead assertion that excludes matches for the exact strings "STRING1" and "STRING2". The $ anchor ensures that the match includes the entire string.
.* matches any character (except newline) zero or more times.