Regular Expressions 101

^start of line

Positive Lookahead(?=[^A-Z]*[A-Z])

Negated Character Class[^A-Z]*

*matches any number of characters outside the set below:

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

Character Class[A-Z]

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

Positive Lookahead(?=[^a-z]*[a-z])

Negated Character Class[^a-z]*

*matches any number of characters outside the set below:

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

Character Class[a-z]

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

Positive Lookahead(?=[^0-9]*[0-9])

Negated Character Class[^0-9]*

*matches any number of characters outside the set below:

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

Character Class[0-9]

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

Negative Lookahead(?!.*(.)\1)

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

Group 1(.)

.any character (except for line terminators)

\1the text saved by group 1

Positive Lookahead(?=[a-zA-Z0-9]*[^A-Za-z0-9\s])

Character Class[a-zA-Z0-9]*

*matches any number of characters from the set below:

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

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

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

Negated Character Class[^A-Za-z0-9\s]

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

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

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

\sany whitespace character

\S{8,}any non-whitespace character, repeated at least 8 times

$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

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Search reference

Regular Expression

^(?=[^A-Z]*[A-Z])(?=[^a-z]*[a-z])(?=[^0-9]*[0-9])(?!.*(.)\1)(?=[a-zA-Z0-9]*[^A-Za-z0-9\s])\S{8,}$

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