Split a text into sentences

php regex string preg-split

10,284

Since you want to "split" sentences why are you trying to match them ?

For this case let's use preg_split().

Code:

$str = 'Fry me a Beaver. Fry me a Beaver! Fry me a Beaver? Fry me Beaver no. 4?! Fry me many Beavers... End';
$sentences = preg_split('/(?<=[.?!])\s+(?=[a-z])/i', $str);
print_r($sentences);

Output:

Array
(
    [0] => Fry me a Beaver.
    [1] => Fry me a Beaver!
    [2] => Fry me a Beaver?
    [3] => Fry me Beaver no. 4?!
    [4] => Fry me many Beavers...
    [5] => End
)

Explanation:

Well to put it simply we are spliting by grouped space(s) \s+ and doing two things:

(?<=[.?!]) Positive look behind assertion, basically we search if there is a point or question mark or exclamation mark behind the space.
(?=[a-z]) Positive look ahead assertion, searching if there is a letter after the space, this is kind of a workaround for the no. 4 problem.

10,284

Author by

thelolcat

Updated on July 14, 2022

Comments

thelolcat almost 2 years
How can I split a text into an array of sentences?

Example text:

Fry me a Beaver. Fry me a Beaver! Fry me a Beaver? Fry me Beaver no. 4?! Fry me many Beavers... End

Should output:
```
0 => Fry me a Beaver.
1 => Fry me a Beaver!
2 => Fry me a Beaver?
3 => Fry me Beaver no. 4?!
4 => Fry me many Beavers...
5 => End
```
I tried some solutions that I've found on SO through search, but they all fail, especially at the 4th sentence.
```
/(?<=[!?.])./

/\.|\?|!/

/((?<=[a-z0-9)][.?!])|(?<=[a-z0-9][.?!]\"))(\s|\r\n)(?=\"?[A-Z])/

/(?<=[.!?]|[.!?][\'"])\s+/    // <- closest one
```
thelolcat almost 11 years

just a question: shouldn't \s be \s+ ? I mean to ignore multiple spaces grouped toghether
HamZa almost 11 years

@thelolcat Well you're right in case there is multiple spaces !
voidMainReturn almost 11 years

@HamZa : what would it translate to be, in java? I tried the same thing in java but it doesn't work. Can you guide me ?
HamZa almost 11 years

@tejas I would guess you need to use double backslash instead of one (?<=[.?!])\\s+(?=[a-z])
voidMainReturn almost 11 years

yes this is what I am using : str.split("(?<=[.?!])\\s+(?=[a-z])"); But of no use.
HamZa almost 11 years

@tejas What do you mean "not correctly" ? Do you mind to join me in the regex chatroom ?
voidMainReturn almost 11 years

actually, the following one worked : str.split("(?<=[.?!])\\s+(?=[a-zA-Z])")
HamZa almost 11 years

@tejas You see that little i after / ? That means match case insensitive. I think you could use my expression and add (?i) to the beginning of it :)
voidMainReturn almost 11 years

yeah ok. I didn't know it's used as ?i in java. I tried using it as /i and it didn't work
HamZa almost 11 years

@tejas not only in Java, it's possible in much more languages.
Cosmologist over 7 years

Thank you! Add it to my helper library - github.com/Cosmologist/Gears/blob/master/src/Gears/StringTyp‌e/…
Ryan about 7 years

I love this and would love it even more if I could disqualify ... from counting as the end of a sentence and include .) as the end of a sentence. Ideas? Thanks.
HamZa about 7 years

@Ryan quick (?<!\.\.\.)(?<=[.?!]|\.\))\s+(?=[a-z]). See if it suits your needs.
Ryan about 7 years

Based on what I learned from yours, I was able to edit it to handle even more corner cases that I'm running into: regex101.com/r/e4NYyd/4 Cool stuff.
Richard almost 6 years

This doesn't work. Try adding "i.e. " to the sentence, this regex fails at this
holden321 over 5 years

Also it doesn't work for sentences with Mr. and !" at the end of sentence.
Markus AO over 3 years

"2020 is the year the system failed." Sentences may start with a digit... which makes avoiding "See (A. 1) for reference." more complex.