Regular Expressions 101

Positive Lookbehind(?<=\.|^)

1st Alternative\.

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

2nd Alternative^

^start of line

Group 1(\d)

\da digit

Positive Lookahead(?=\.|$)

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.

Search reference

Regular Expression

(?<=\.|^)(\d)(?=\.|$)

New

1
1.
1.2
1.2.
1.2.3
1.2.3.