Regular Expressions 101

Explanation

Pro

^start of string

Group 1([a-z][a-z0-9_.]+@([a-z0-9-]+\.)+[a-z]{2,6}(,\s{0,1}){0,1})+

+repeats the group contents below at least once:

Character Class[a-z]

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

Character Class[a-z0-9_.]+

+matches at least one character from the set below:

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

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

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

.the literal . (46₁₀ / 56₈ / 2E₁₆)

@the literal @ (64₁₀ / 100₈ / 40₁₆)

Group 2([a-z0-9-]+\.)+

+repeats the group contents below at least once:

Character Class[a-z0-9-]+

+matches at least one character from the set below:

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

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

-the literal - (45₁₀ / 55₈ / 2D₁₆)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Character Class[a-z]{2,6}

{2,6}matches between 2 and 6 characters from the set below:

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

Group 3(,\s{0,1}){0,1}

{0,1}repeats the group contents below at most once:

,the literal , (44₁₀ / 54₈ / 2C₁₆)

\s{0,1}optionally matches any whitespace character

$end of string, or before its final line terminator

No unit tests

Add a test to get started

25 tokens

^([a-z][a-z0-9_.]+@([a-z0-9-]+\.)+[a-z]{2,6}(,\s{0,1}){0,1})+$

There are no unit tests.