Regular Expressions 101

Negative Lookbehind(?<!\..*)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

.*any character (except for line terminators), repeated any number of times

Group 1(\d)

\da digit

Positive Lookahead(?=(?:\d{3})+(?:\.|$))

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

+repeats the group contents below at least once:

\d{3}a digit, repeated exactly 3 times

Non-Capturing Group(?:\.|$)

1st Alternative\.

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

2nd Alternative$

$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.

26 tokens

Regular Expression

(?<!\..*)(\d)(?=(?:\d{3})+(?:\.|$))

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