Extract a string between 2 characters of the same character

Question

I understand how to extract a string between 2 DIFFERENT types of strings like [ and ], or ( ), etc...

But what I don't know is how to get multiple/all strings between 1 character. Eg:

the *big* brown fox *jumps over* the *lazy* **dog**

it should return for "*":

big
jumps over
lazy

and it should also return for "**":

dog

All libraries, regex patterns and such don't support such a feature.

Create your own method that respects your conditions and build your output strings with stringbuilder — Ricardo, Apr 26 '16 at 12:59
you need regexp matching with a groups like "(\*\w+\*)" and "(\*\*\w+\*\*)" See http://stackoverflow.com/questions/5508965/java-regexp-group-capturing — kofemann, Apr 26 '16 at 13:02

dryairship · Answer 1 · 2016-04-26T13:19:27.450

5

This regex :

[\*]+([a-z ]*)[\*]+

will match what you are looking for. See this.

[\*]+ at the end matches 1 or more *s.
([a-z ]*) matches the characters between a-z and the space, and returns that.

Now since Andy turner points out that it also matches dog in *dog*********, You can do:

[\*]{1,2}([a-z ]*)[\*]{1,2}

This would match *s between 1 and 2. (See this) You can change that to any range, but note that {1,3} will match 1,2 or 3 times, and not only 1 and 3 times.

edited Apr 26 '16 at 13:19

answered Apr 26 '16 at 13:03

dryairship

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This doesn't quite work - it doesn't match the same start and end. For instance, it would match `*dog**********` (and for `**dog**` it would match `**` and `**`). – Andy Turner Apr 26 '16 at 13:05
1

@AndyTurner You are right. But that wasn't a requirement. Was it? – dryairship Apr 26 '16 at 13:07
@AndyTurner No. for `**dog**`. It would match `dog` Seen the link? – dryairship Apr 26 '16 at 13:08
@MilanvanDijck No it doesn't. `[\*]+` tries to match as many `*`s as possible. So, they are already gone. we only return the part between `(` and `)` – dryairship Apr 26 '16 at 13:09
Oh, OK. But it does match `*dog**********`. – Andy Turner Apr 26 '16 at 13:14
@AndyTurner Yeah, but OP doesn't say that it shouldn't.. ;) – dryairship Apr 26 '16 at 13:16

score 0 · Answer 2 · answered Apr 26 '16 at 13:04

0

String str="the *big* brown fox *jumps over* the *lazy* **dog**"    
str = str.replace("**", "*");

and then perform the extraction method you were using

answered Apr 26 '16 at 13:04

user6218508

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There is a more elegant way to solve it (with regular expressions) but this is not wrong and should not be down-voted. – Milan van Dijck Apr 26 '16 at 13:11

score 0 · Answer 3 · edited Apr 29 '16 at 03:38

0

String test = "the *big* brown fox *jumps over* the *lazy* **dog**";

StringTokenizer st = new StringTokenizer(test,"*");

while (st.hasMoreTokens()) {
    System.out.println(st.nextToken());
}

edited Apr 29 '16 at 03:38

hichris123

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answered Apr 26 '16 at 13:24

K.S.R

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Extract a string between 2 characters of the same character

3 Answers3