Regular Expressions 101

Explanation

Pro

Positive Lookahead(?=^[A-Za-z\d -\/:-@[-`{-~À-ÿ]{8,30}$)

^start of line

Character Class[A-Za-z\d -\/:-@[-`{-~À-ÿ]{8,30}

{8,30}matches between 8 and 30 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

-\/one character from (32₁₀) to / (47₁₀)

:-@one character from : (58₁₀) to @ (64₁₀)

[-`one character from [ (91₁₀) to ` (96₁₀)

{-~one character from { (123₁₀) to ~ (126₁₀)

À-ÿone character from À (192₁₀) to ÿ (255₁₀) (case sensitive)

$end of line

^start of line

Non-Capturing Group(?:[A-Za-z\d]*[ -\/:-@[-`{-~À-ÿ]){0,3}

{0,3}repeats the group contents below between 0 and 3 times:

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

Character Class[ -\/:-@[-`{-~À-ÿ]

-\/one character from (32₁₀) to / (47₁₀)

:-@one character from : (58₁₀) to @ (64₁₀)

[-`one character from [ (91₁₀) to ` (96₁₀)

{-~one character from { (123₁₀) to ~ (126₁₀)

À-ÿone character from À (192₁₀) to ÿ (255₁₀) (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

$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

Match Information

Detailed match information will be displayed here automatically.

Quick Reference

25 tokens

Regular Expression

(?=^[A-Za-z\d -\/:-@[-`{-~À-ÿ]{8,30}$)^(?:[A-Za-z\d]*[ -\/:-@[-`{-~À-ÿ]){0,3}[A-Za-z\d]*$

New

AABBCCDD
OK -- Match

aabbccdd
OK -- Match

11111111
OK -- Match

A1A1b2b2
OK -- Match

A@~D1dIo
OK -- Match

AAB BCC0
OK -- Match (1 special, it's okay)

AABBCC@@
OK -- Match (2 specials, it's okay)

AABB  C 
OK -- Match (3 specials, it's okay)

A@~`  C:
OK -- Match (3 specials, it's okay)

AABB
OK -- Should't match and didn't match (Less than 8 symbols)

AABBCCDDEEFFGGHHIIJJKKLLMMNNOOPP
OK -- Should't match and didn't match (More than 30 symbols)

AA@@@@BB
ERROR ! -- Shouldn't match (4 specials, it's forbidden)

AAB    B
ERROR ! -- Shouldn't match (4 specials, it's forbidden)

AABB@@@@
ERROR ! -- Shouldn't match (4 specials, it's forbidden)