Regular Expressions 101

^start of line

Group firstchar(?<firstchar>(?=[A-Za-z]))

Positive Lookahead(?=[A-Za-z])

Character Class[A-Za-z]

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

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

Group 2((?<alphachars>[A-Za-z])|(?<specialchars>[A-Za-z]['-](?=[A-Za-z]))|(?<spaces> (?=[A-Za-z])))*

*repeats the group contents below any number of times:

1st Alternative(?<alphachars>[A-Za-z])

Group alphachars(?<alphachars>[A-Za-z])

Character Class[A-Za-z]

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

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

2nd Alternative(?<specialchars>[A-Za-z]['-](?=[A-Za-z]))

Group specialchars(?<specialchars>[A-Za-z]['-](?=[A-Za-z]))

Character Class[A-Za-z]

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

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

Character Class['-]

'the literal ' (39₁₀ / 47₈ / 27₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

Positive Lookahead(?=[A-Za-z])

Character Class[A-Za-z]

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

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

3rd Alternative(?<spaces> (?=[A-Za-z]))

Group spaces(?<spaces> (?=[A-Za-z]))

the literal (32₁₀ / 40₈ / 20₁₆)

Positive Lookahead(?=[A-Za-z])

Character Class[A-Za-z]

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

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

$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

Search reference

Regular Expression

^(?<firstchar>(?=[A-Za-z]))((?<alphachars>[A-Za-z])|(?<specialchars>[A-Za-z]['-](?=[A-Za-z]))|(?<spaces> (?=[A-Za-z])))*$

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