Regular Expressions 101

Explanation

Pro

\ban ASCII word boundary

Group 1(\d{7}(?:\d{3,19})?)

\d{7}a digit, repeated exactly 7 times

Non-Capturing Group(?:\d{3,19})?

?repeats the group contents below at most once:

\d{3,19}a digit, repeated between 3 and 19 times

\ban ASCII word boundary

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

Detailed match information will be displayed here automatically.

25 tokens

\b(\d{7}(?:\d{3,19})?)\b

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