Regular Expressions 101

Pro

#the literal # (35₁₀ / 43₈ / 23₁₆)

Group 1([1-3]\d{4}(?: E\d{6})?)

Character Class[1-3]

1-3one character from 1 (49₁₀) to 3 (51₁₀)

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

Non-Capturing Group(?: E\d{6})?

?repeats the group contents below at most once:

Ethe literal text E (case sensitive)

\d{6}a Unicode decimal digit, repeated exactly 6 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

Detailed match information will be displayed here automatically.

25 tokens

#([1-3]\d{4}(?: E\d{6})?)$

New

successful my registration id is #12345 E112233
Successful my data is #22331 E001122
failing    12345