Regular Expressions 101

Explanation
Pro

Group 1(http(s)?:[/]{2})?

?repeats the group contents below at most once:

httpthe literal text http (case sensitive)

Group 2(s)?

?repeats the group contents below at most once:

sthe literal s (115₁₀ / 163₈ / 73₁₆) (case sensitive)

:the literal : (58₁₀ / 72₈ / 3A₁₆)

Character Class[/]{2}

{2}matches exactly 2 characters from the set below:

/the literal / (47₁₀ / 57₈ / 2F₁₆)

Group 3([a-z0-9][a-z0-9\-]+.)+

+repeats the group contents below at least once:

Character Class[a-z0-9]

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

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

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)

.any character (except for line terminators)

Group 4([a-z0-9\-])+

+repeats the group contents below at least once:

Character Class[a-z0-9\-]

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)

Global pattern flags

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

Detailed match information will be displayed here automatically.

26 tokens

(http(s)?:[/]{2})?([a-z0-9][a-z0-9\-]+.)+([a-z0-9\-])+

New

http://aaa.com.tw
https://aa-a.com.tw
http://aaa.com
https://aaa.com
aaa.com
aaa.com.tw

http://aaa.com.tw
https://aa-a.com.tw
http://aaa.com
https://aaa.com
aaa.com
aaa.com.tw