Regular Expressions 101

Pro

^start of line

Group 1(([-+])?(\d+)?n)?

?repeats the group contents below at most once:

Group 2([-+])?

?repeats the group contents below at most once:

Character Class[-+]

-the literal - (45₁₀ / 55₈ / 2D₁₆)

+the literal + (43₁₀ / 53₈ / 2B₁₆)

Group 3(\d+)?

?repeats the group contents below at most once:

\d+a digit, repeated at least once

nthe literal n (110₁₀ / 156₈ / 6E₁₆) (case sensitive)

\+?optionally matches the literal + (43₁₀ / 53₈ / 2B₁₆)

Group 4(\d+)?

?repeats the group contents below at most once:

\d+a digit, repeated at least once

$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

26 tokens

^(([-+])?(\d+)?n)?\+?(\d+)?$