Regular Expressions 101

Pro

^start of line

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

Non-Capturing Group(?:0*[1-9][0-9]*\.[0-9]*|0\.0*[1-9][0-9]*)

1st Alternative0*[1-9][0-9]*\.[0-9]*

0*the literal 0 (48₁₀ / 60₈ / 30₁₆) , repeated any number of times

Character Class[1-9]

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

Character Class[0-9]*

*matches any number of characters from the set below:

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

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Character Class[0-9]*

*matches any number of characters from the set below:

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

2nd Alternative0\.0*[1-9][0-9]*

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

0*the literal 0 (48₁₀ / 60₈ / 30₁₆) , repeated any number of times

Character Class[1-9]

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

Character Class[0-9]*

*matches any number of characters 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.

25 tokens

^-?(?:0*[1-9][0-9]*\.[0-9]*|0\.0*[1-9][0-9]*)$

New

0.12
1.00
1.12
-0.12
-1.00
-1.12
-10.010

without matching negative zeros:
-0
-0.0
-0.00