Regular Expressions 101

Positive Lookbehind(?<=\s|^)

1st Alternative\s

\sany whitespace character

2nd Alternative^

^start of line

Group 1([a-z0-9-.])+

+repeats the group contents below at least once:

Character Class[a-z0-9-.]

a-zone character from a (97₁₀) to z (122₁₀) (case sensitive)

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

-the literal - (45₁₀ / 55₈ / 2D₁₆)

.the literal . (46₁₀ / 56₈ / 2E₁₆)

@+the literal @ (64₁₀ / 100₈ / 40₁₆) , repeated at least once

Group 2([a-z0-9-]*)

Character Class[a-z0-9-]*

*matches any number of characters from the set below:

a-zone character from a (97₁₀) to z (122₁₀) (case sensitive)

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

-the literal - (45₁₀ / 55₈ / 2D₁₆)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Group 3([a-z]*)

Character Class[a-z]*

*matches any number of characters from the set below:

a-zone character from a (97₁₀) to z (122₁₀) (case sensitive)

\sany whitespace character

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

(?<=\s|^)([a-z0-9-.])+@+([a-z0-9-]*)\.([a-z]*)\s

New

this regex is intended to find emails with tld level 1 from a text test@domain12.com this a text after email to check detection
test@domain12.com this is another text to test regex for that i had to write down some email something-new@gmail.com to another.email@gmail.com test123@domain-12.com test@domain.co
sample@organization.org test.abc@domain.ac.nz test@abc.co
example@testdomain.net

Regular Expression

Extraction