Regular Expression for any non-empty consecutive sequence of 0's enclosed between 1

Question

I need to find all the groups in a String having consecutive sequence of 0's enclosed between 1

100001abc101 // 2 groups `100001` and `101`
1001ab010abc01001 // 2 groups `1001' and `1001`
1001010001 // 3 groups `1001`, `101` and `10001` --> This is a special case

My Regex for the same is: 1(0+)1 this is working good for 1st and 2nd case but in 3rd test case It's only matching 1001 and 10001 not 101

Please suggest what I am missing.

The problem is match starts from the next character of last matched group, it should start from the same matched character itself.

Answer 1

To match overlapping matches, you should be using a capturing group inside a lookahead like this:

(?=(10+1))

RegEx Demo

Since we are only asserting matches instead of matching them, regex engine is able to return all possible combinations of 10+1 even if they are overlapping.

Answer 2

Try a look-behind and look-ahead instead, since you don't actually want to match the 1s:

/(?<=1)0+(?=1)/

https://regex101.com/r/IGygJj/3