What does "-" mean inside [ ] in regular expression?

Asked Mar 23 '20 at 14:29

Active Mar 23 '20 at 14:31

Viewed 26 times

I was trying to match "kit - kat" or "kit-kat" for one of my ElasticSearch project.

and I wanted it to become "kitkat". So i was writting an char_filter.

To achieve the above mentioned result i was writing a Regular Expression in https://regex101.com

First i wrote a REGEX which looked like this "(\S+)[ |-|_]*".

It didn't worked as expected (wrong expectation!).

But when i did this it worked "(\S+)[ |\-|_]*".

What is the meaning of - in []?

edited Mar 23 '20 at 14:31

asked Mar 23 '20 at 14:29

Abhinav Keshri

1

In `[...]`, `-` defines a range – Wiktor Stribiżew Mar 23 '20 at 14:30
Thanks a lot. I finally got it. – Abhinav Keshri Mar 23 '20 at 14:39
1

If it is a Lucene engine, the hyphen at the start of the character class is treated as a literal `-`. At any other position in the character class, it must be escaped. – Wiktor Stribiżew Mar 23 '20 at 15:05
that is kind of weird. – Abhinav Keshri Mar 24 '20 at 03:50

0 Answers0