Regular Expressions 101

^start of line

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)

Group 1((?=.*\d)|(?=.*\W))

1st Alternative(?=.*\d)

Positive Lookahead(?=.*\d)

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

\da digit

2nd Alternative(?=.*\W)

Positive Lookahead(?=.*\W)

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

\Wany non-word character

.{10,20}any character (except for line terminators), repeated between 10 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

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

^(?=.*[a-zA-Z])((?=.*\d)|(?=.*\W)).{10,20}$

12344A.ffdsaaddd
12344aaav
12344aaavq
fffffffffffasdfasdfas
A**.2344aaavq