Regular Expressions 101

Pro

^start of line

Character Class[+-]?

?matches at most one character from the set below:

+the literal + (43₁₀ / 53₈ / 2B₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

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

1st Alternative\d+(?:\.\d+)?

\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

2nd Alternative\.\d+

\.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

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

New

0.00000
0.00
-100
+100
-100.1
+100.1
.000
.1
3.
4.

0.00000
0.00
-100
+100
-100.1
+100.1
.000
.1
3.
4.