negating words with Java regular expressions

[Raj Ashar]

All, I would like to know if Java's implementation of regular
expressions allows for the negation of a word. I know that it is
possible to negate members of a character class with "[^...]" to avoid
matching against those characters, and that it is possible to match
for a string by specifying the members of the string in a regular
expression (eg "my first regex"), but I'm not sure if there's a way to
match selectively (ie match all instances of ";" except where ".;.").

Thank you.

Raj

 

[Chris Smith]

but I'm not sure if there's a way to
match selectively (ie match all instances of ";" except where ".;.").

Pattern.compile("[^\\.]\\;[^\\.]");

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[Carl Howells]

but I'm not sure if there's a way to
match selectively (ie match all instances of ";" except where ".;.").

Pattern.compile("[^\\.]\\;[^\\.]");

Nope. That won't do. You're matching all instances of
"<something>;<something>", except when both <something>s are ".". But
that isn't what was requested. That won't match either semicolon in the
string "; hello! ;", for instance. It also grabs the characters on
either side of the semicolon, which is not what was requested, either.

Try:

Pattern.compile("(?<!\\.);(?!\\.)");

I haven't tested it, but it should work.