Regular Expressions 101

Positive Lookahead(?=.*\d)

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

\da digit

Character Class[A-Za-z0-9]{1,11}

{1,11}matches between 1 and 11 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

Detailed match information will be displayed here automatically.

26 tokens

Regular Expression

(?=.*\d)[A-Za-z0-9]{1,11}

New

a1
12345678901
a1b2c3d4e56
432432324ll
k343242432k
kkkkkkkkkkk
2342343249
asdmsd1kfds