Regular Expressions 101

Explanation

Pro

Group 1((?<![\w.])[+-]?(?:\d+\.\d+|\d+\.|\.\d+|\d+)(?:[eE][+-]?\d+)?(?![\w.]))

Negative Lookbehind(?<![\w.])

Character Class[\w.]

\wany word character

.the literal . (46₁₀ / 56₈ / 2E₁₆)

Character Class[+-]?

?matches at most one character from the set below:

+the literal + (43₁₀ / 53₈ / 2B₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

Non-Capturing Group(?:\d+\.\d+|\d+\.|\.\d+|\d+)

1st Alternative\d+\.\d+

\d+a digit, repeated at least once

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\d+a digit, repeated at least once

2nd Alternative\d+\.

\d+a digit, repeated at least once

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

3rd Alternative\.\d+

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\d+a digit, repeated at least once

4th Alternative\d+

\d+a digit, repeated at least once

Non-Capturing Group(?:[eE][+-]?\d+)?

?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 + (43₁₀ / 53₈ / 2B₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

\d+a digit, repeated at least once

Negative Lookahead(?![\w.])

Character Class[\w.]

\wany word character

.the literal . (46₁₀ / 56₈ / 2E₁₆)

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

Match Information

Detailed match information will be displayed here automatically.

Quick Reference

25 tokens

Regular Expression

((?<![\w.])[+-]?(?:\d+\.\d+|\d+\.|\.\d+|\d+)(?:[eE][+-]?\d+)?(?![\w.]))

a a aaaainput 1.5e8 100 1e8 1000e3 1. .2 .3e-3 -3 +3 abcd 1 192.168.100.1 1 192.168. 1 .129.12 1.5 .3ee 1 .3e+e 1 3fgh 1 .3sdf 1 asdf3 0 asdf3asdf -111.555e-100 +99.99e+99

Extraction

a a aaaainput 1.5e8 100 1e8 1000e3 1. .2 .3e-3 -3 +3 abcd 1 192.168.100.1 1 192.168. 1 .129.12 1.5 .3ee 1 .3e+e 1 3fgh 1 .3sdf 1 asdf3 0 asdf3asdf -111.555e-100 +99.99e+99