anything not starting with a given word
Matches anything not starting with a given word. It is anchored at both ends, so the whole string has to match. There are no capture groups.
Pattern
/^(?!test)\w+$/- Match scope
- the whole string
- Capture groups
- 0
- What it catches in the first example
- prod
Try it yourself
Type any text and the parts this expression catches are highlighted. It runs in your browser and is never sent anywhere.
prod
1 match
Examples that match
- prod
- abc
Examples that do not match
- test
- testing
Other expressions in this group
^(?!.* ).+$text with no double space anywhere^(?=.*@).+$text that must contain this sign\B(?=(\d{3})+(?!\d))the spot where a thousands comma goes^(?!.*(.)\1).+$no character repeated back to back(?<=₩)\d+digits that follow a won sign^(?!.*\btest\b).*$a line that does not contain a given word^.*(?<=\.png)$anything ending with a given suffix^(?!.*\d\d).*$text with no two digits in a rowHow to read this
- With ^ and $ around it, the whole string must match; without them the match can sit anywhere. Always anchor an expression you use for validation.
- Round brackets ( ) capture what they wrap. When you only need grouping, write (?: ) so the numbering of later groups does not shift.
- Every expression here is checked against its examples. Even so, "looks like an email" and "is a real inbox" remain different questions.
- Nested open-ended repeats such as (a+)+ can blow up on certain inputs. Look for that shape before pasting someone else’s expression into your code.
Frequently asked questions
Q. What is the regex for anything not starting with a given word?
^(?!test)\w+$.
Q. Which strings match?
Text like prod matches; text like test does not.
Q. Does the whole string have to match?
Yes. It is wrapped in ^ and $, so nothing but a full match passes.
Q. How do I use what it caught?
There are no capture groups, so only the whole match (match[0]) comes back. Wrap the part you need in brackets to capture it.