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Pattern
(.)\1
Input
a
bb
cc
c
dd
dd
abbcccdddd
Options
Ignore Case
Ignore Whitespace
Explicit Capture
Culture Invariant
Singleline
Multiline
Right To Left
ECMA Script
Start from position:
Max matches to find:
Replacement
Replace matches with...
${1}2
Click the
context
tab to see replacements.
Regex Info
Table
Context
Split List
4
matches found in about
4
milliseconds.
Show Permalink
Permalink
Index
Position
Matched String
Replacement
$1
0
1
bb
b2
b
1
3
cc
c2
c
2
6
dd
d2
d
3
8
dd
d2
d
a
b2
c2
c
d2
d2
a
b
empty string
c
c
d
empty string
d
empty string
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