Regular Expressions 101

Explanation

Pro

^start of line

Non-Capturing Group(?:[+-]\d+|(?:[01][0-9]|2[0-3]):[0-5][0-9])

1st Alternative[+-]\d+

Character Class[+-]

+the literal + (43₁₀ / 53₈ / 2B₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

\d+a digit, repeated at least once

2nd Alternative(?:[01][0-9]|2[0-3]):[0-5][0-9]

Non-Capturing Group(?:[01][0-9]|2[0-3])

1st Alternative[01][0-9]

Character Class[01]

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

Character Class[0-9]

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

2nd Alternative2[0-3]

2the literal 2 (50₁₀ / 62₈ / 32₁₆)

Character Class[0-3]

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

:the literal : (58₁₀ / 72₈ / 3A₁₆)

Character Class[0-5]

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

Character Class[0-9]

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

$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

Detailed match information will be displayed here automatically.

25 tokens

^(?:[+-]\d+|(?:[01][0-9]|2[0-3]):[0-5][0-9])$

New

+120
-15
17:56
18:89
-
+

+120
-15
17:56
18:89
-
+