Regular Expressions 101

^start of line

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

Negated Character Class[^A-Z\n]*

*matches any number of characters outside the set below:

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

\na line-feed (newline) character (ASCII 10)

Character Class[A-Z]

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

Negated Character Class[^A-Z\n]*

*matches any number of characters outside the set below:

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

\na line-feed (newline) character (ASCII 10)

$end of line

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

Negated Character Class[^a-z\n]*

*matches any number of characters outside the set below:

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

\na line-feed (newline) character (ASCII 10)

Character Class[a-z]

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

Negated Character Class[^a-z\n]*

*matches any number of characters outside the set below:

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

\na line-feed (newline) character (ASCII 10)

$end of line

Positive Lookahead(?=(?:[^\d\n]*\d){6}[^\d\n]*$)

Non-Capturing Group(?:[^\d\n]*\d){6}

{6}repeats the group contents below exactly 6 times:

Negated Character Class[^\d\n]*

*matches any number of characters outside the set below:

\da digit

\na line-feed (newline) character (ASCII 10)

\da digit

Negated Character Class[^\d\n]*

*matches any number of characters outside the set below:

\da digit

\na line-feed (newline) character (ASCII 10)

$end of line

Character Class[a-zA-Z0-9]{8}

{8}matches exactly 8 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)

$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

No unit tests · Add a test to get started

26 tokens

Regular Expression

^(?=[^A-Z\n]*[A-Z][^A-Z\n]*$)(?=[^a-z\n]*[a-z][^a-z\n]*$)(?=(?:[^\d\n]*\d){6}[^\d\n]*$)[a-zA-Z0-9]{8}$

Unit Tests

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