Capturing quantifiers

Question

I have a regex pattern to capture three group:

(([abc])([abc])([abc]))

How can I rewrite this in the other way?

I tried:

(([abc]){1,3})

But only the last group was captured.

Thanks in advance.

it only capture the last group (https://regex101.com/r/kX8aB7/1) — Hoang Hong Khang, Mar 30 '15 at 13:14
use: (([abc])([abc])([abc])), capture each of group MATCH 1 1. [0-3] `abc` 2. [0-1] `a` 3. [1-2] `b` 4. [2-3] `c` — Hoang Hong Khang, Mar 30 '15 at 13:42

score 1 · Answer 1 · answered Mar 30 '15 at 14:00

1

If I got your point, you want to capture groups of "abc" as a whole bloc. For example, abcabcabc and not abcabbc. If it's the case, then you should use (abc){1,3}. See https://regex101.com/r/kX8aB7/3

answered Mar 30 '15 at 14:00

riroo

134
3
15

score 0 · Accepted Answer · answered Mar 30 '15 at 13:58

You can't do this differently unless you use certain regex-engines (I believe .net supports it). If you repeat a capture-group, a repeated match will override the earlier found match of that capture-group. That's why you end up with only the last match.

This is of course a limitation if you don't know how many instances of a sub-pattern are gonna appear but you want to capture each individual match of the sub-pattern in a capture group.

One way around this, depending on the (programming) environment, is to match the repeated pattern as 1 bigger capture group and then run a new regex on the found capture. Example:

var inp = 'some string that matches regex & ac but we don\'t know how many letters after the regex';

var m = inp.match(/(regex).*?([abc]{1,3})/);
          
document.getElementById('out').value=m[2].match(/[abc]/g).join('\n');

<textarea id="out" rows="5" style="width:100%"></textarea>

Capturing quantifiers

2 Answers2