Regular Expressions 101

Positive Lookahead(?=\b.{11}\b)

\ban ASCII word boundary

.{11}any character (except for line terminators), repeated exactly 11 times

\ban ASCII word boundary

Character Class[0-9]{1,4}

{1,4}matches between 1 and 4 characters from the set below:

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

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

Character Class[0-9]{1,4}

{1,4}matches between 1 and 4 characters from the set below:

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

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

Character Class[0-9]{1,4}

{1,4}matches between 1 and 4 characters from the set below:

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

Global pattern flags

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

Detailed match information will be displayed here automatically.

25 tokens

Regular Expression

(?=\b.{11}\b)[0-9]{1,4}\/[0-9]{1,4}\/[0-9]{1,4}

New

12/3456/789
123/4567/89
1234/5/6789
123/456/789
12/3456/7890

12/3456/789
123/4567/89
1234/5/6789
123/456/789
12/3456/7890