Regular Expressions 101

^start of line

Character Class[+-]?

?matches at most one character from the set below:

+the literal + (43₁₀ / 53₈ / 2B₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

\d+a Unicode decimal digit, repeated at least once

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

?repeats the group contents below at most once:

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\d*a Unicode decimal digit, repeated any number of times

Negative Lookbehind(?<!.{6})

.{6}any Unicode character (except for line terminators), repeated exactly 6 times

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

Regular Expression

^[+-]?\d+(?:\.\d*)?(?<!.{6})

New

123
        ->   123
1.23
       ->   1.23
123456
     ->   12345
+12.34
     ->   +12.3
-12.34
     ->   -12.3
1.2-3
      ->   1.2
1.2.3.4
    ->   1.2
....