Regular Expressions 101

Explanation

Pro

^start of line

Non-Capturing Group(?:(?=.*[a-zA-Z])(?=.*[\d])|(?=.*[!#+,.\\=:=@-])(?=.*[\d])|(?=.*[!#+,.\\=:=@-])(?=.*[a-zA-Z]))

1st Alternative(?=.*[a-zA-Z])(?=.*[\d])

Positive Lookahead(?=.*[a-zA-Z])

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

Character Class[a-zA-Z]

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

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

Positive Lookahead(?=.*[\d])

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

Character Class[\d]

\da digit

2nd Alternative(?=.*[!#+,.\\=:=@-])(?=.*[\d])

Positive Lookahead(?=.*[!#+,.\\=:=@-])

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

Character Class[!#+,.\\=:=@-]

!the literal ! (33₁₀ / 41₈ / 21₁₆)

#the literal # (35₁₀ / 43₈ / 23₁₆)

+the literal + (43₁₀ / 53₈ / 2B₁₆)

,the literal , (44₁₀ / 54₈ / 2C₁₆)

.the literal . (46₁₀ / 56₈ / 2E₁₆)

\\the literal \ (92₁₀ / 134₈ / 5C₁₆)

=the literal = (61₁₀ / 75₈ / 3D₁₆)

:the literal : (58₁₀ / 72₈ / 3A₁₆)

@the literal @ (64₁₀ / 100₈ / 40₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

Positive Lookahead(?=.*[\d])

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

Character Class[\d]

\da digit

3rd Alternative(?=.*[!#+,.\\=:=@-])(?=.*[a-zA-Z])

Positive Lookahead(?=.*[!#+,.\\=:=@-])

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

Character Class[!#+,.\\=:=@-]

!the literal ! (33₁₀ / 41₈ / 21₁₆)

#the literal # (35₁₀ / 43₈ / 23₁₆)

+the literal + (43₁₀ / 53₈ / 2B₁₆)

,the literal , (44₁₀ / 54₈ / 2C₁₆)

.the literal . (46₁₀ / 56₈ / 2E₁₆)

\\the literal \ (92₁₀ / 134₈ / 5C₁₆)

=the literal = (61₁₀ / 75₈ / 3D₁₆)

:the literal : (58₁₀ / 72₈ / 3A₁₆)

@the literal @ (64₁₀ / 100₈ / 40₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

Positive Lookahead(?=.*[a-zA-Z])

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

Character Class[a-zA-Z]

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

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

.{8,20}any character (except for line terminators), repeated between 8 and 20 times

$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

^(?:(?=.*[a-zA-Z])(?=.*[\d])|(?=.*[!#+,.\\=:=@-])(?=.*[\d])|(?=.*[!#+,.\\=:=@-])(?=.*[a-zA-Z])).{8,20}$

New

jingjing20
jingjingjing
jingjing.