Regex to match end-of-sentence markers

Question

I need to match all the end-of-sentence symbols like !, ?, . (period), etc. in a given body of text.

Can anyone help me out with the regex for doing such a thing?

Example Input:

This is the f!!rst sentence! Is this the second one? The third sentence is here... And the fourth one!!

Output:

This is the f!!rst sentence Is this the second one The third sentence is here And the fourth one

While asking any question, please keep in mind to give sample input and expected output. This will prevent answers solely based on assumptions. — TheLostMind, Sep 23 '14 at 08:19
People will help you if you ask a question that's useful to more than just you. Which is not the case here. — Mena, Sep 23 '14 at 08:24
Sorry, I was in a bit of a hurry as I needed this for a my University project, basically I am building a search engine prototype and I need to tokenize each word in the data source which contains 10,000+ news articles. One of the tasks of filtering is to remove symbols like !,?,. which occur at the end of sentences as markers. — user2306772, Sep 23 '14 at 08:33

vks · Accepted Answer · 2014-09-23T09:01:26.440

1

[!?.]+(?=$|\s)

Try this.You can add markers as needed.Replace by ``.

See demo.

http://regex101.com/r/lS5tT3/15

edited Sep 23 '14 at 09:01

answered Sep 23 '14 at 08:42

vks

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Exactly what I wanted! Thank you. By the way, can you recommend a good way to learn reg expressions? I need to master this stuff sooner or later, so I need a good place where I can start from – user2306772 Sep 23 '14 at 08:49
@user2306772 see your exmaple.you have removed everything from middle as well.correct it first. – vks Sep 23 '14 at 08:52
Hope the question is clear now! – user2306772 Sep 23 '14 at 08:55
Ok, Ive probably had a little too much Red Bull to drink... Sorry again! – user2306772 Sep 23 '14 at 08:57
@user2306772 why are `?` and '.' between your string missing? – vks Sep 23 '14 at 08:58
@user2306772 this doesnt seem to be red bull.Should be some beer :) – vks Sep 23 '14 at 08:59

lance-java · Answer 2 · 2014-09-23T08:39:02.840

0

You'd probably want to match anything (.*?) followed by the end of sentence followed by whitespace (\s+). Since !, ? and . are special characters, you'll need to excape them.

eg

Pattern pattern = Pattern.compile("(.*?)[\\!\\?\\.]\\s+");
Matcher matcher = pattern.matcher("one two. three! four five? ");
while (matcher.find()) {
   System.out.println(matcher.group(1));
}

prints

one two
three
four five

edited Sep 23 '14 at 08:39

answered Sep 23 '14 at 08:28

lance-java

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This answer isn't particularly helpful to anyone. The question itself isn't clear. – TheLostMind Sep 23 '14 at 08:31
Seriously? I think I've explained enough to get the brain thinking. Next time I won't bother. – lance-java Sep 23 '14 at 08:33
I probably screwed up by asking the question in a very casual manner. I was in a hurry and needed some quick help, and didnt bother elaborating much. Anyways, I have made an edit. Lance Java, your answer was certainly helpful, but I suppose that is not what I was looking for. – user2306772 Sep 23 '14 at 08:41

Avinash Raj · Answer 3 · 2014-09-23T08:59:38.020

0

The below regex would match the non-word characters (except spaces) which must be followed by a space character or end of the line anchor. replaceAll function helps to remove all the matched characters.

String s = "Blah! blah? blah... blah blah!!";
System.out.println(s.replaceAll("[^\\w\\s]+(?=\\s|$)", ""));

Output:

Blah blah blah blah blah

If you want to remove only ?, ., ! characters which was present at the last in a word, you could try the below code.

String s = "This is the f!!rst sentence! Is this the second one? The third sentence is here... And the fourth one!!";
System.out.println(s.replaceAll("[!?.]+(?=\\s|$)", ""));

Output:

This is the f!!rst sentence Is this the second one The third sentence is here And the fourth one

edited Sep 23 '14 at 08:59

answered Sep 23 '14 at 08:54

Avinash Raj

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Thanks a ton! Both vks' solution and your's worked just fine! – user2306772 Sep 23 '14 at 09:04
@user2306772 you did not try the edited one – vks Sep 23 '14 at 09:05
@vks i posted the answer before your edit. See the revisions. – Avinash Raj Sep 23 '14 at 09:06
@AvinashRaj the question kept on changing. – vks Sep 23 '14 at 09:06
Sorry for the mess! Next time around, I should spend some time elaborating on the question more clearly – user2306772 Sep 23 '14 at 09:09

Regex to match end-of-sentence markers

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