Regular Expressions 101

^start of string

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(?=.*\d)

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

\da digit

Positive Lookahead(?=.*[\W\_])

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

Character Class[\W\_]

\Wany non-word character

\_the literal _ (95₁₀ / 137₈ / 5F₁₆)

Character Class[A-Za-z\d\W\_]{8,}

{8,}matches at least 8 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)

\da digit

\Wany non-word character

\_the literal _ (95₁₀ / 137₈ / 5F₁₆)

$end of string, or before its final line terminator

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[\W\_])[A-Za-z\d\W\_]{8,}$