Regular Expressions 101

^start of string

Group 1([A-Za-z]{1}[A-Za-z\d_]*\.)*

*repeats the group contents below any number of times:

Character Class[A-Za-z]{1}

{1}matches one character from the set below:

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

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

Character Class[A-Za-z\d_]*

*matches any number of characters from the set below:

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

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

\da digit

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

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[A-Za-z\d_]*

*matches any number of characters from the set below:

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

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

\da digit

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

$end of string, or before its final line terminator

Global pattern flags

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

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

^([A-Za-z]{1}[A-Za-z\d_]*\.)*[A-Za-z][A-Za-z\d_]*$

New

Com.facbook.Ka1nama_foo