Regular Expressions 101

^start of string

Positive Lookahead(?=.*?[0-9])

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

Character Class[0-9]

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

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

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

Character Class[a-z]

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

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

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

Character Class[A-Z]

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

Positive Lookahead(?=.*?[^\w\s])

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

Negated Character Class[^\w\s]

\wany word character

\sany whitespace character

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

$end of string, or before its final line terminator

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

^(?=.*?[0-9])(?=.*?[a-z])(?=.*?[A-Z])(?=.*?[^\w\s]).{8,20}$

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