Regex keep greedy even when using lazy quantifier

Question

Here is my regex ^((\{.+:.+\})|([^{:}]))+?$.

Here is what i want:
Valid case: {test:test1} {test2:test3} test4 test5.
Invalid case: {test:}, {test1: test2, test1: test3}.

It's mean whenever my string have one of this three character: '{' ':', '}' it must also have 2 remaning character.

My regex is working well when my string not end with } character. I guess it's because of greedy quantifier. But i already put ? character after + quantifier it's still not working. What am I doing wrong?

Try `^(?:\{[^{}:]*:[^:{}]*}|[^{:}])+$`, see [demo](https://regex101.com/r/RrtZh3/1) — Wiktor Stribiżew, Oct 09 '18 at 10:57
Wow its working, thank you all!, but i dont understand so much, can u guys explain for me? Thank you! — Thanh Phong, Oct 09 '18 at 11:02

score 1 · Accepted Answer · answered Oct 09 '18 at 11:03

You may use

^(?:\{[^{}:]*:[^:{}]*}|[^{:}])+$

See the regex demo.

Details

^ - start of string
(?:\{[^{}:]*:[^:{}]*}|[^{:}])+ - a non-capturing group matching 1 or more occurrences of
- \{[^{}:]*:[^:{}]*} - a {, then any 0+ chars other than {, } and :, then :, then any 0+ chars other than {, } and :, and a }
- | - or
- [^{:}] - any char but {, } and :
$ - end of string.

Regex keep greedy even when using lazy quantifier

1 Answers1