Regular Expressions 101

Positive Lookahead(?=(\d+)\1+(.*))

Group 1(\d+)

\d+a digit, repeated at least once

\1+the text saved by group 1, repeated at least once

Group 2(.*)

.*any character (except for line terminators), repeated any number of times

Group 3(\d+?)

\d+?a digit, repeated at least once

\3+the text saved by group 3, repeated at least once

\2the text saved by group 2

$end of string, or before its final line terminator

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

(?=(\d+)\1+(.*))(\d+?)\3+\2$

New

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