Regex Groups and Capturing
Capture, name, and backreference parts of a match.
- regex groups
- named group
- backreference
- non-capturing
- regex replace
Regex Groups and Capturing
Capture, name, and backreference parts of a match.
Commands
| Command | What it does |
|---|---|
(\d+)-(\d+) | Two numbered groups |
(?<year>\d{4}) | Named group called year |
(?:...) | Non-capturing group |
\1 | Backreference to group 1 |
\k<year> | Backreference to a named group |
Example
(?<y>\d{4})-(?<m>\d{2})-(?<d>\d{2})FAQ
When should I use non-capturing groups?
For pure grouping with alternation or quantifiers - it keeps group numbers stable and matching fast.
How do replacements reference groups?
Dollar-1 in JS and backslash-1 in Python; named groups read best in complex rewrites.
FAQ
When should I use non-capturing groups?
For pure grouping with alternation or quantifiers - it keeps group numbers stable and matching fast.
How do replacements reference groups?
Dollar-1 in JS and backslash-1 in Python; named groups read best in complex rewrites.