I need to parse the url /domain.com?filter[a.b.c]=value1&filter[a.b.d]=value2
and get 2 groups: 'a.b.c' and 'a.b.d'.
I try to parse with regexp [\?&]filter\[(.+\..+)+\]= but the result is 'a.b.c]=value1&filter[a.b.d'. How can I specify to search for the 1st occurrence?
You may use
/[?&]filter\[([^\].]+\.[^\]]+)]=/g
See the regex demo
Details
[?&] - a ? or &filter\[ - a filter[ substring([^\].]+\.[^\]]+) - Capturing group 1:
[^\].]+ - 1 or more chars other than ] and .\. - a dot[^\]]+ - 1 or more chars other than ] ]= - a ]= substringJS demo:
var s = '/domain.com?filter[a.b.c]=value1&filter[a.b.d]=value2';
var rx = /[?&]filter\[([^\].]+\.[^\]]+)]=/g;
var m, res=[];
while(m=rx.exec(s)) {
res.push(m[1]);
}
console.log(res);Note that in case & is never present as part of the query param value, you may add it to the negated character classes, [^\].]+ => [^\]&.]+, to make sure the regex does not overmatch across param values.
Since you need to extract text inside outer square brackets that may contain consecutive [...] substrings with at least 1 dot inside one of them, you may use a simpler regex with a bit more code:
var strs = ['/domain.com?filter[a.b.c]=value1&filter[a.b.d]=value2',
'/domain.com?filter[a.b.c]=value1&filter[a.b.d]=value2&filter[a][b.e]=value3',
'/domain.com?filter[a.b.c]=value1&filter[b][a.b.d][d]=value2&filter[a][b.e]=value3'];
var rx = /[?&]filter((?:\[[^\][]*])+)=/g;
for (var s of strs) {
var m, res=[];
console.log(s);
while(m=rx.exec(s)) {
if (m[1].indexOf('.') > -1) {
res.push(m[1].substring(1,m[1].length-1));
}
}
console.log(res);
console.log("--- NEXT STRING ----");
}
/domain.com?filter[a.b.c]=value1&filter[a.b.d]=value2&filter[a][b.e]=value3 We should to get 3 groups: 'a.b.c', 'a.b.d' and 'a][b.e' (or 'b.e.')
[?&]filter\[([^=.]+\.[^\]]+)]= Is it have any problems?[^=.]+ matches any 1+ chars other than = and . (i.e. it matches [ and ], and may match a part of one value and then the whole substring till the matching ending part).(?<=[\?&]filter\[)([^\]]+\.[^\]]+)+(?!>\]=)
This will give you only the groups you mentioned (a.b.c and a.b.d)
This part (?<=[\?&]filter\[) says recognise but don't capture [?&]filter before what you want and this part (?!>\]=) says recognise but don't capture after ] after what you want.
[^\]] this captures everything that isn't a square bracket
