Regular Expressions 101

Pro

1st Alternative\b0(?!9*~)

\ban ASCII word boundary

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

Negative Lookahead(?!9*~)

9*the literal 9 (57₁₀ / 71₈ / 39₁₆) , repeated any number of times

~the literal ~ (126₁₀ / 176₈ / 7E₁₆)

2nd Alternative([0-9])(?=9*~[0-9]*?\1([0-9]))

Group 1([0-9])

Character Class[0-9]

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

Positive Lookahead(?=9*~[0-9]*?\1([0-9]))

9*the literal 9 (57₁₀ / 71₈ / 39₁₆) , repeated any number of times

~the literal ~ (126₁₀ / 176₈ / 7E₁₆)

Character Class[0-9]*?

*?matches any number of characters from the set below:

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

\1the text saved by group 1

Group 2([0-9])

Character Class[0-9]

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

3rd Alternative~[0-9]*

~the literal ~ (126₁₀ / 176₈ / 7E₁₆)

Character Class[0-9]*

*matches any number of characters from the set below:

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

Global pattern flags

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

Detailed match information will be displayed here automatically.

26 tokens

\b0(?!9*~)|([0-9])(?=9*~[0-9]*?\1([0-9]))|~[0-9]*

New

01~01234567890

$2

01~01234567890