Regular Expressions 101

Pro

^start of line

Non-Capturing Group(?:[a-zA-Z0-9]|\s\B){12}

{12}repeats the group contents below exactly 12 times:

1st Alternative[a-zA-Z0-9]

Character Class[a-zA-Z0-9]

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

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

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

2nd Alternative\s\B

\sa Unicode whitespace character

\Bnot a Unicode word boundary

$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.

25 tokens

^(?:[a-zA-Z0-9]|\s\B){12}$

New

abC123def456
abc123dEf45 
abc123def4  
sd45f45FFFRd

 abc123def45
abc123 ef456
123
sd45f45FFFR

abC123def456
abc123dEf45 
abc123def4  
sd45f45FFFRd

 abc123def45
abc123 ef456
123
sd45f45FFFR