Regular Expressions 101

^start of line

-?optionally matches the literal - (45₁₀ / 55₈ / 2D₁₆)

\d*a digit, repeated any number of times

Group 1(\.\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.

Search reference

Regular Expression

^-?\d*(\.\d+)?$

New

100
10.2
0.5
0.
.5
-0.5
-100
abcd