Regular Expressions 101

Explanation

Pro

^start of string

Group 1(([0-9]+)-?)+

+repeats the group contents below at least once:

Group 2([0-9]+)

Character Class[0-9]+

+matches at least one character from the set below:

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

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

Negated Character Class[^-]

-the literal - (45₁₀ / 55₈ / 2D₁₆)

Character Class[0-9]*

*matches any number of characters from the set below:

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

$end of string, or before its final line terminator

Ready to run

25 tokens

^(([0-9]+)-?)+[^-][0-9]*$