Regex not operator

Solution 1:

Not quite, although generally you can usually use some workaround on one of the forms

• [^abc], which is character by character not a or b or c,
• or negative lookahead: a(?!b), which is a not followed by b
• or negative lookbehind: (?<!a)b, which is b not preceeded by a

Solution 2:

No, there's no direct not operator. At least not the way you hope for.

You can use a zero-width negative lookahead, however:

\((?!2001)[0-9a-zA-z _\.\-:]*\)

The (?!...) part means "only match if the text following (hence: lookahead) this doesn't (hence: negative) match this. But it doesn't actually consume the characters it matches (hence: zero-width).

There are actually 4 combinations of lookarounds with 2 axes:

• lookbehind / lookahead : specifies if the characters before or after the point are considered
• positive / negative : specifies if the characters must match or must not match.