C# Backreference Constructs

Backreference constructs allow a previously matched sub-expression to be identified subsequently in the same regular expression.

The following table lists these constructs −

Backreference construct Description Pattern Matches
\ number Backreference. Matches the value of a numbered subexpression. (\w)\1 "ee" in "seek"
\k< name > Named backreference. Matches the value of a named expression. (?< char>\w)\k< char> "ee" in "seek"