Regular Expressions 101

Explanation
Pro

^start of line

\d+a digit, repeated at least once

Non-Capturing Group(?:\.\d+)*

*repeats the group contents below any number of times:

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\d+a digit, repeated at least once

Negative Lookahead(?!\S)

\Sany non-whitespace character

Negative Lookahead(?!.*\d)

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

\da digit

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

^\d+(?:\.\d+)*(?!\S)(?!.*\d)

New

1 Match
1.1 Match
45.67.21234.3 Match
1 Does not match1
12. Does not match
123

1 Match
1.1 Match
45.67.21234.3 Match
1 Does not match1
12. Does not match
123