Regular Expressions 101

Pro

Positive Lookbehind(?<=\d{6})

\d{6}a digit, repeated exactly 6 times

Group 1(\d+)

\d+a digit, repeated at least once

Positive Lookahead(?=\d{4})

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

Global pattern flags

U modifier: Ungreedy. Quantifiers are lazy by default. A trailing ? makes a quantifier greedy

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

Detailed match information will be displayed here automatically.

25 tokens

(?<=\d{6})(\d+)(?=\d{4})

New

4548812049400004
5229782641993099
345678000000007
6362970000457013

X

4548812049400004
5229782641993099
345678000000007
6362970000457013