Regular Expressions 101

Pro

^start of line

Group 1((?:(\d{4}-\d{2}-\d{2})T(\d{2}:\d{2}:\d{2}(?:\.\d+)?))(Z|[\+-]\d{2}:\d{2})?)

Non-Capturing Group(?:(\d{4}-\d{2}-\d{2})T(\d{2}:\d{2}:\d{2}(?:\.\d+)?))

Group 2(\d{4}-\d{2}-\d{2})

\d{4}a digit, repeated exactly 4 times

-the literal - (45₁₀ / 55₈ / 2D₁₆)

\d{2}a digit, repeated exactly 2 times

-the literal - (45₁₀ / 55₈ / 2D₁₆)

\d{2}a digit, repeated exactly 2 times

Tthe literal T (84₁₀ / 124₈ / 54₁₆) (case sensitive)

Group 3(\d{2}:\d{2}:\d{2}(?:\.\d+)?)

\d{2}a digit, repeated exactly 2 times

:the literal : (58₁₀ / 72₈ / 3A₁₆)

\d{2}a digit, repeated exactly 2 times

:the literal : (58₁₀ / 72₈ / 3A₁₆)

\d{2}a digit, repeated exactly 2 times

Non-Capturing Group(?:\.\d+)?

?repeats the group contents below at most once:

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\d+a digit, repeated at least once

Group 4(Z|[\+-]\d{2}:\d{2})?

?repeats the group contents below at most once:

1st AlternativeZ

Zthe literal Z (90₁₀ / 132₈ / 5A₁₆) (case sensitive)

2nd Alternative[\+-]\d{2}:\d{2}

Character Class[\+-]

\+the literal + (43₁₀ / 53₈ / 2B₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

\d{2}a digit, repeated exactly 2 times

:the literal : (58₁₀ / 72₈ / 3A₁₆)

\d{2}a digit, repeated exactly 2 times

$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

Ready to run

25 tokens

^((?:(\d{4}-\d{2}-\d{2})T(\d{2}:\d{2}:\d{2}(?:\.\d+)?))(Z|[\+-]\d{2}:\d{2})?)$