Regular Expressions 101

Explanation

Pro

Positive Lookahead(?=(?:\d*[A-Za-z]))

Non-Capturing Group(?:\d*[A-Za-z])

\d*a digit, repeated any number of times

Character Class[A-Za-z]

A-Zone character from A (65₁₀) to Z (90₁₀) (case sensitive)

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

Positive Lookahead(?=(?:\S*?[A-Z]){3,}\S*?$)

Non-Capturing Group(?:\S*?[A-Z]){3,}

{3,}repeats the group contents below at least 3 times:

\S*?any non-whitespace character, repeated any number of times

Character Class[A-Z]

A-Zone character from A (65₁₀) to Z (90₁₀) (case sensitive)

\S*?any non-whitespace character, repeated any number of times

$end of line

Positive Lookahead(?=(?:[a-zA-Z]*\d))

Non-Capturing Group(?:[a-zA-Z]*\d)

Character Class[a-zA-Z]*

*matches any number of characters from the set below:

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

A-Zone character from A (65₁₀) to Z (90₁₀) (case sensitive)

\da digit

Character Class[A-Za-z0-9]{5,30}

{5,30}matches between 5 and 30 characters from the set below:

A-Zone character from A (65₁₀) to Z (90₁₀) (case sensitive)

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

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

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

(?=(?:\d*[A-Za-z]))(?=(?:\S*?[A-Z]){3,}\S*?$)(?=(?:[a-zA-Z]*\d))[A-Za-z0-9]{5,30}

New

Detect

https://stackoverflow.com/%22Abcde3FGhiDE%22Zyx23
|a|b|c|AbcdEFGH123|456Ac
P A Abcde3Dd3FGhiDE Z H
ZZ123!Abcde3FGhiDE!123

Don't detect

IAMoverTHELIMITTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTT3
NULLLLLLLLLLLLLLLLLLLLLLllll
|A|b|c|D|E|F|1|
<HeLLoWoRlD"123

Substitution

Detect

https://stackoverflow.com/%22Abcde3FGhiDE%22Zyx23
|a|b|c|AbcdEFGH123|456Ac
P A Abcde3Dd3FGhiDE Z H
ZZ123!Abcde3FGhiDE!123

Don't detect

IAMoverTHELIMITTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTT3
NULLLLLLLLLLLLLLLLLLLLLLllll
|A|b|c|D|E|F|1|
<HeLLoWoRlD"123