Regular Expressions 101

Explanation
Pro

^start of line

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

Group 1(\d|[1-9]+\d*|\.\d+|0\.\d+|[1-9]+\d*\.\d+)

1st Alternative\d

\da digit

2nd Alternative[1-9]+\d*

Character Class[1-9]+

+matches at least one character from the set below:

1-9one character from 1 (49₁₀) to 9 (57₁₀)

\d*a digit, repeated any number of times

3rd Alternative\.\d+

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\d+a digit, repeated at least once

4th Alternative0\.\d+

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\d+a digit, repeated at least once

5th Alternative[1-9]+\d*\.\d+

Character Class[1-9]+

+matches at least one character from the set below:

1-9one character from 1 (49₁₀) to 9 (57₁₀)

\d*a digit, repeated any number of times

\.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|[1-9]+\d*|\.\d+|0\.\d+|[1-9]+\d*\.\d+)$