Regular Expressions 101

Pro

^start of line

Negative Lookahead(?!\d+\.)

\d+a digit, repeated at least once

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Group 1([\p{L}0-9][\p{L}0-9\-]{0,24}[\p{L}0-9])

Character Class[\p{L}0-9]

\p{L}any Unicode letter

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

Character Class[\p{L}0-9\-]{0,24}

{0,24}matches between 0 and 24 characters from the set below:

\p{L}any Unicode letter

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

\-the literal - (45₁₀ / 55₈ / 2D₁₆)

Character Class[\p{L}0-9]

\p{L}any Unicode letter

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

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

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

Detailed match information will be displayed here automatically.

25 tokens

^(?!\d+\.)([\p{L}0-9][\p{L}0-9\-]{0,24}[\p{L}0-9])\.

New

estadão.com.br
domínio.com.br
90.com
-errado.com
aindaerrado-.com
OK.com
1.com.br
1a.org
łðµsdaf.com
estadao.com

estadão.com.br
domínio.com.br
90.com
-errado.com
aindaerrado-.com
OK.com
1.com.br
1a.org
łðµsdaf.com
estadao.com