Regular Expressions 101

^start of line

Group prefix(?<prefix>retour-)?

?repeats the group contents below at most once:

retour-the literal text retour- (case sensitive)

\s*a Unicode whitespace character, repeated any number of times

Group trackingNumber(?<trackingNumber>\d+)

\d+a Unicode decimal digit, repeated at least once

\s*a Unicode whitespace character, repeated any number of times

Group postfix(?<postfix>-(\d+))?

?repeats the group contents below at most once:

-the literal - (45₁₀ / 55₈ / 2D₁₆)

Group 4(\d+)

\d+a Unicode decimal 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

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

^(?<prefix>retour-)?\s*(?<trackingNumber>\d+)\s*(?<postfix>-(\d+))?$

New

# Does not match:
1234ABC3456
retour-123456-12B

# Matches:
retour-123456-123
123456-123
123456