Regular Expressions 101

Pro

^start of line

Negative Lookahead(?!\s+-)

\s+any whitespace character, repeated at least once

-the literal - (45₁₀ / 55₈ / 2D₁₆)

Negated Character Class[^\n%-]{1,10}

{1,10}matches between 1 and 10 characters outside the set below:

\na line-feed (newline) character (ASCII 10)

%the literal % (37₁₀ / 45₈ / 25₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

Negative Lookahead(?!\s+-)

\s+any whitespace character, repeated at least once

-the literal - (45₁₀ / 55₈ / 2D₁₆)

Negated Character Class[^\n%-]{1,12}

{1,12}matches between 1 and 12 characters outside the set below:

\na line-feed (newline) character (ASCII 10)

%the literal % (37₁₀ / 45₈ / 25₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

\d{4,9}a digit, repeated between 4 and 9 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.

25 tokens

Regular Expression

^(?!\s+-)[^\n%-]{1,10}-(?!\s+-)[^\n%-]{1,12}-\d{4,9}$

allowed strings:

1sAS-c$AS-01238
t t-c:t-012345678
t$t-c 2:t-012345678

Not allowed strings:

1sA%S-c$AS-01238
   (because this contains % in the first word)
 -c:t-01235678
     (because this contains only space in the first word)
t$t- -01234578
     (because this contains only space in the 2nd word)
t-$t-check-012378
  (because this contains more hypens)