Regular Expressions 101

Group 1([a-z])

Character Class[a-z]

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

Negative Lookahead(?!\1)

\1the text saved by group 1

Group 2([a-z])

Character Class[a-z]

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

\2the text saved by group 2

\1the text saved by group 1

Negative Lookahead(?![^[]*])

Negated Character Class[^[]*

*matches any number of characters outside the set below:

[the literal [ (91₁₀ / 133₈ / 5B₁₆)

]the literal ] (93₁₀ / 135₈ / 5D₁₆)

Global pattern flags

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

Detailed match information will be displayed here automatically.

25 tokens

Regular Expression

([a-z])(?!\1)([a-z])\2\1(?![^[]*])

New

baab[pqrs]asdf yes boobs
abcd[pqqp]xzzx no ..cc.
bbbb[zxcv]bnmkop no
adad ddss sdds ssssdds
ixooxj[kjhgfd]mnbvcxz yes
iubduyyr[exauibqlf]ytrddstz no
extoxp[bylubaahxfxiesk]brpqqpbo yes

axxa