Regular Expressions 101

Explanation
Pro

^start of line

Character Class[-+]?

?matches at most one character from the set below:

-the literal - (45₁₀ / 55₈ / 2D₁₆)

+the literal + (43₁₀ / 53₈ / 2B₁₆)

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

?repeats the group contents below at most once:

1st Alternative[1-9]*[0-9]?\.

Character Class[1-9]*

*matches any number of characters from the set below:

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

Character Class[0-9]?

?matches at most one character from the set below:

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

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

2nd Alternative0\.

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

\.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)

Group 2([eE][-+]?[0-9]+)?

?repeats the group contents below at most once:

Character Class[eE]

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

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

Character Class[-+]?

?matches at most one character from the set below:

-the literal - (45₁₀ / 55₈ / 2D₁₆)

+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

Match Information

Detailed match information will be displayed here automatically.

Quick Reference

25 tokens

Regular Expression

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

0.000000
-0.00000
+0.0000
.1
+.1
-.1
+00000.1
-00000.1
000000000000000.1
000.1111
00.11
0.1
-0.1
+0.1
1.1
+1.1
-1.1
10.11
+10.11
+10.11
100.11
+100.11
-100.11
1000.111
+1000.111
-1000.111

Extraction

0.000000
-0.00000
+0.0000
.1
+.1
-.1
+00000.1
-00000.1
000000000000000.1
000.1111
00.11
0.1
-0.1
+0.1
1.1
+1.1
-1.1
10.11
+10.11
+10.11
100.11
+100.11
-100.11
1000.111
+1000.111
-1000.111