Text Processingflags: g
Named Capture Group (Date)
Demonstrate named capture groups by extracting year/month/day from ISO-style dates.
Try it in RegexPro →Available in
Pattern
regexengine-agnostic
(?<year>\d{4})-(?<month>\d{2})-(?<day>\d{2}) (flags: g)Raw source: (?<year>\d{4})-(?<month>\d{2})-(?<day>\d{2})
How it works
(?<year>\d{4}) captures four digits under the name 'year'; (?<month>\d{2}) and (?<day>\d{2}) likewise. Modern JS, Python 3.7+, and Go (with `(?P<...>)` syntax — JS-style is also accepted in Python 3.12+) all support this; the matched substring is accessible by name in code (e.g. m.groups.year in JS, m['year'] in Python).
Examples
Input
Born 1990-05-21, hired 2018-09-10Matches
1990-05-212018-09-10
Input
Today is 2026-04-25Matches
2026-04-25
Input
no dates hereNo match
—Common use cases
- •Self-documenting regex in production code
- •Extracting structured fields from log lines
- •Form field validation with named outputs
- •Building parsers without positional bookkeeping