Regular Expressions 101

Pro

Positive Lookahead(?=^.{8,}$)

^start of line

.{8,}any character (except for line terminators), repeated at least 8 times

$end of line

Negative Lookahead(?!^\d)

^start of line

\da digit

Negative Lookahead(?!.*\d$)

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

\da digit

$end of line

Negative Lookahead(?!.+\d\d)

.+any character (except for line terminators), repeated at least once

\da digit

Positive Lookahead(?=.*[&%$^#@=])

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

Character Class[&%$^#@=]

&the literal & (38₁₀ / 46₈ / 26₁₆)

%the literal % (37₁₀ / 45₈ / 25₁₆)

$the literal $ (36₁₀ / 44₈ / 24₁₆)

^the literal ^ (94₁₀ / 136₈ / 5E₁₆)

#the literal # (35₁₀ / 43₈ / 23₁₆)

@the literal @ (64₁₀ / 100₈ / 40₁₆)

=the literal = (61₁₀ / 75₈ / 3D₁₆)

Positive Lookahead(?=(.*[A-Z]){2})

Group 1(.*[A-Z]){2}

{2}repeats the group contents below exactly 2 times:

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

Character Class[A-Z]

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

Positive Lookahead(?=(.*[a-z]){2})

Group 2(.*[a-z]){2}

{2}repeats the group contents below exactly 2 times:

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

Character Class[a-z]

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

Positive Lookahead(?=(.*[0-9]){2})

Group 3(.*[0-9]){2}

{2}repeats the group contents below exactly 2 times:

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

Character Class[0-9]

0-9one character from 0 (48₁₀) to 9 (57₁₀)

Global pattern flags

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

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

Detailed match information will be displayed here automatically.

26 tokens

Regular Expression

(?=^.{8,}$)(?!^\d)(?!.*\d$)(?!.+\d\d)(?=.*[&%$^#@=])(?=(.*[A-Z]){2})(?=(.*[a-z]){2})(?=(.*[0-9]){2})

aa1$1BB
bbAZ9$Zfx
bbAZ9$Zf
b8A9$Zfy
b7AZ9$fy
b8A$Zfy4
6bA$Z8yt
7bA$Z8y4
b8A$Z47y
b8A$ZSyg
b8A$Z8yg
b8A$xf4y
A8bb=4cd
12345678AA1bb2=a