Regular Expressions 101

Pro

1st Alternative\b0*1(?=0+~)

\ban ASCII word boundary

0*the literal 0 (48₁₀ / 60₈ / 30₁₆) , repeated any number of times

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

Positive Lookahead(?=0+~)

0+the literal 0 (48₁₀ / 60₈ / 30₁₆) , repeated at least once

~the literal ~ (126₁₀ / 176₈ / 7E₁₆)

2nd Alternative\b0+

\ban ASCII word boundary

0+the literal 0 (48₁₀ / 60₈ / 30₁₆) , repeated at least once

3rd Alternative([0-9])(?=0*~[0-9]*?\1([0-9]))

Group 1([0-9])

Character Class[0-9]

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

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

0*the literal 0 (48₁₀ / 60₈ / 30₁₆) , 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)

4th 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.

25 tokens

Regular Expression

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

New

000~09876543210
0001~09876543210
1~09876543210
2~09876543210
3~09876543210
004~09876543210
10~09876543210
0010~09876543210
0020~09876543210
210~09876543210
438~09876543210
1000~09876543210

Extraction

000~09876543210
0001~09876543210
1~09876543210
2~09876543210
3~09876543210
004~09876543210
10~09876543210
0010~09876543210
0020~09876543210
210~09876543210
438~09876543210
1000~09876543210