Regular Expressions 101

^start of line

Non-Capturing Group(?:.*?(\w[^@\s]*@[^@\s]{2,}).*?|.+)

1st Alternative.*?(\w[^@\s]*@[^@\s]{2,}).*?

.*?any character (except for line terminators), repeated any number of times

Group 1(\w[^@\s]*@[^@\s]{2,})

\wany word character

Negated Character Class[^@\s]*

*matches any number of characters outside the set below:

@the literal @ (64₁₀ / 100₈ / 40₁₆)

\sany whitespace character

@the literal @ (64₁₀ / 100₈ / 40₁₆)

Negated Character Class[^@\s]{2,}

{2,}matches at least 2 characters outside the set below:

@the literal @ (64₁₀ / 100₈ / 40₁₆)

\sany whitespace character

.*?any character (except for line terminators), repeated any number of times

2nd Alternative.+

.+any character (except for line terminators), repeated at least once

$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

^(?:.*?(\w[^@\s]*@[^@\s]{2,}).*?|.+)$

New

Sample text for testing:
abcdefghijklmnopqrstuvwxyz ABCDEFGHIJKLMNOPQRSTUVWXYZ
0123456789 _+-.,!@#$%^&*();\/|<>"'
12345 -98.7 3.141 .6180 9,000 +42
555.123.4567	+1-(800)-555-2468
foo@demo.net	bar.ba@test.co.uk
www.demo.com	http://foo.co.uk/
http://regexr.com/foo.html?q=bar

This is a line with an email@person.com email address

Substitution

\1