Regular Expressions 101

Pro

Non-Capturing Group(?:0?[1-9]|[1-2][0-9]|30|31)

1st Alternative0?[1-9]

0?optionally matches the literal 0 (48₁₀ / 60₈ / 30₁₆)

Character Class[1-9]

1-9one character from 1 (49₁₀) to 9 (57₁₀)

2nd Alternative[1-2][0-9]

Character Class[1-2]

1-2one character from 1 (49₁₀) to 2 (50₁₀)

Character Class[0-9]

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

3rd Alternative30

30the literal text 30

4th Alternative31

31the literal text 31

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

(?:0?[1-9]|[1-2][0-9]|30|31)

New