Regular Expressions 101

Explanation

Pro

1st Alternative^(?:-|[0-9]).*

^start of string

Non-Capturing Group(?:-|[0-9])

1st Alternative-

-the literal - (45₁₀ / 55₈ / 2D₁₆)

2nd Alternative[0-9]

Character Class[0-9]

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

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

2nd Alternative(?<=\n\n)(?:-|[0-9])(?:.|\n)*?(?=\n+[^-0-9]|$)

Positive Lookbehind(?<=\n\n)

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

Non-Capturing Group(?:-|[0-9])

1st Alternative-

-the literal - (45₁₀ / 55₈ / 2D₁₆)

2nd Alternative[0-9]

Character Class[0-9]

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

Non-Capturing Group(?:.|\n)*?

*?repeats the group contents below any number of times:

1st Alternative.

.any Unicode character (except for line terminators)

2nd Alternative\n

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

Positive Lookahead(?=\n+[^-0-9]|$)

1st Alternative\n+[^-0-9]

\n+a line-feed (newline) character (ASCII 10), repeated at least once

Negated Character Class[^-0-9]

-the literal - (45₁₀ / 55₈ / 2D₁₆)

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

2nd Alternative$

$end of string, or before its final line terminator

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

Detailed match information will be displayed here automatically.

25 tokens

^(?:-|[0-9]).*|(?<=\n\n)(?:-|[0-9])(?:.|\n)*?(?=\n+[^-0-9]|$)

New

- one

some text
- should not start a list

- should start
- should continue

5. should also
6. more

- one

some text
- should not start a list

- should start
- should continue

5. should also
6. more