Regular Expressions 101

^start of line

Group 1(0*[1-9]\d{0,9}(\.\d{0,2})?0*|0*\.([1-9]|\d[1-9]|[1-9]\d)0*)

1st Alternative0*[1-9]\d{0,9}(\.\d{0,2})?0*

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)

\d{0,9}a digit, repeated between 0 and 9 times

Group 2(\.\d{0,2})?

?repeats the group contents below at most once:

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\d{0,2}a digit, repeated between 0 and 2 times

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

2nd Alternative0*\.([1-9]|\d[1-9]|[1-9]\d)0*

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

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Group 3([1-9]|\d[1-9]|[1-9]\d)

1st Alternative[1-9]

Character Class[1-9]

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

2nd Alternative\d[1-9]

\da digit

Character Class[1-9]

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

3rd Alternative[1-9]\d

Character Class[1-9]

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

\da digit

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

$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

^(0*[1-9]\d{0,9}(\.\d{0,2})?0*|0*\.([1-9]|\d[1-9]|[1-9]\d)0*)$

New

0
.0
.00
0.0
.
00016515464645
-1
-1.2
1..1
1.1.1
..1
..1.1
-
.-
-.16
111111111111111111
1.11111111
1.584646

00000.13
00000000014.15
1
1.2
0.2
.1
20
20.0
20.00
20.
1641616515
0001641616515
0165154646
20.00000000
0.1100000000000
1234567890.11

Regular Expression

Substitution