Regular Expressions 101

Pro

Group 1([0-1]?\d|2[0-3])

1st Alternative[0-1]?\d

Character Class[0-1]?

?matches at most one character from the set below:

0-1one character from 0 (48₁₀) to 1 (49₁₀)

\da digit

2nd Alternative2[0-3]

2the literal 2 (50₁₀ / 62₈ / 32₁₆)

Character Class[0-3]

0-3one character from 0 (48₁₀) to 3 (51₁₀)

Non-Capturing Group(?::([0-5]?\d))?

?repeats the group contents below at most once:

:the literal : (58₁₀ / 72₈ / 3A₁₆)

Group 2([0-5]?\d)

Character Class[0-5]?

?matches at most one character from the set below:

0-5one character from 0 (48₁₀) to 5 (53₁₀)

\da digit

Non-Capturing Group(?::([0-5]?\d))

:the literal : (58₁₀ / 72₈ / 3A₁₆)

Group 3([0-5]?\d)

Character Class[0-5]?

?matches at most one character from the set below:

0-5one character from 0 (48₁₀) to 5 (53₁₀)

\da digit

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]?\d|2[0-3])(?::([0-5]?\d))?(?::([0-5]?\d))

New

00:00:00
00:00:01
23:59:17
01:01:01
10:17:25
09:56:17
22:56:59

00:00:00
00:00:01
23:59:17
01:01:01
10:17:25
09:56:17
22:56:59