Regular Expressions 101

^start of line

Group 1(([A-Za-z\d])\2(?!.*\2)){3}

{3}repeats the group contents below exactly 3 times:

Group 2([A-Za-z\d])

Character Class[A-Za-z\d]

A-Zone character from A (65₁₀) to Z (90₁₀) (case sensitive)

a-zone character from a (97₁₀) to z (122₁₀) (case sensitive)

\da digit

\2the text saved by group 2

Negative Lookahead(?!.*\2)

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

\2the text saved by group 2

$end of line

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

Detailed match information will be displayed here automatically.

25 tokens

Regular Expression

^(([A-Za-z\d])\2(?!.*\2)){3}$

New

RRFFKK
BB7733
WWDDMM
5599AA
555677
AABBCD
55AA55
6699bb
66782376

RRFFKK
BB7733
WWDDMM
5599AA
555677
AABBCD
55AA55
6699bb
66782376