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 digit, repeated at least once

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

?repeats the group contents below at most once:

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\d+a digit, repeated at least once

$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.

25 tokens

Regular Expression

^[+-]?\d+(?:\.\d+)?$

New

52.3
42
-6
52.0
0.61
+0.6

Does not match:
52.
abc
test
1.6.1.4
192.0.0.1
-6.0.1
+.8
++6
-6-
-3.