Regular Expressions 101

^start of line

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

Character Class[0-9]+

+matches at least one character from the set below:

0-9one character from 0 (48₁₀) to 9 (57₁₀)

Non-Capturing Group(?:\.[0-9]+)?

?repeats the group contents below at most once:

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Character Class[0-9]+

+matches at least one character from the set below:

0-9one character from 0 (48₁₀) to 9 (57₁₀)

Non-Capturing Group(?:(?:e|E)(?:-|\+)?[0-9]+)?

?repeats the group contents below at most once:

Non-Capturing Group(?:e|E)

1st Alternativee

ethe literal e (101₁₀ / 145₈ / 65₁₆) (case sensitive)

2nd AlternativeE

Ethe literal E (69₁₀ / 105₈ / 45₁₆) (case sensitive)

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

?repeats the group contents below at most once:

1st Alternative-

-the literal - (45₁₀ / 55₈ / 2D₁₆)

2nd Alternative\+

\+the literal + (43₁₀ / 53₈ / 2B₁₆)

Character Class[0-9]+

+matches at least one character from the set below:

0-9one character from 0 (48₁₀) to 9 (57₁₀)

$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.

27 tokens

Regular Expression

^-?[0-9]+(?:\.[0-9]+)?(?:(?:e|E)(?:-|\+)?[0-9]+)?$

New

100
-100
12.34
4e10
4.2e-2
9e+5
1.2.3
v100
10.
.01