Regular Expressions 101

^start of line

Group 1([0-9]-?){8}

{8}repeats the group contents below exactly 8 times:

Character Class[0-9]

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

-?optionally matches the literal - (45₁₀ / 55₈ / 2D₁₆)

$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

^([0-9]-?){8}$

New

12345678
123456-78
1234-5678
1-2-3-4-5-6-7-8