Regular Expressions 101

^start of line

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

1st Alternative0\.0*

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

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

2nd Alternative[+-]?(?:(?!0\.0*$)0|[1-9][0-9]*)?\.[0-9]+

Character Class[+-]?

?matches at most one character from the set below:

+the literal + (43₁₀ / 53₈ / 2B₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

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

?repeats the group contents below at most once:

1st Alternative(?!0\.0*$)0

Negative Lookahead(?!0\.0*$)

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

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

$end of line

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

2nd Alternative[1-9][0-9]*

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 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.

Search reference

Regular Expression

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

New

float varieties:

4848.48
20.20
20.2000000
-1.23
-0.23
+1.1
0.45
+0.45
-0.45
0.0
0.00000
-0.0
+0.0
.3
-.4
+.4
+.30
00.1
+00001.1
01.45
+01.20
-00.2


int varieties:

1234
43210
12012
+1
0
-0
+0
01234
000001234
+00
-00
+00123
-00123