Does anyone have a PHP snippet of code for grabbing the first "sentence" in a string?

Question

If I have a description like:

"We prefer questions that can be answered, not just discussed. Provide details. Write clearly and simply."

and all I want is "We prefer questions that can be answered, not just discussed."

I figure I would search for a regular expression, like "[.!\?]", determine the strpos and then do a substr from the main string, but I imagine it's a common thing to do, so hoping someone has a snippet lying around.

Thanks!

Answer 1

<?php
$text = "We prefer questions that can be answered, not just discussed. Provide details. Write clearly and simply.";
$array = explode('.',$text);
$text = $array[0];
?>

Answer 2

 reset(explode('.', $s, 2));

Answer 3

A slightly more costly expression, however will be more adaptable if you wish to select multiple types of punctuation as sentence terminators.

   $sentence = preg_replace('/([^?!.]*.).*/', '\\1', $string);

Find termination characters followed by a space

   $sentence = preg_replace('/(.*?[?!.](?=\s|$)).*/', '\\1', $string);

Answer 4

current(explode(".",$input));

Answer 5

I'd probably use any of the multitudes of substring/string-split functions in PHP (some mentioned here already). But also look for ". " OR ".\n" (and possibly ".\n\r") instead of just ".". Just in case for whatever reason, the sentence contains a period that isn't followed by a space. I think it will harden the likelihood of you getting genuine results.

Example, searching for just "." on:

"I like stackoverflow.com."

Will get you:

"I like stackoverflow."

When really, I'm sure you'd prefer:

"I like stackoverflow.com."

And once you have that basic search, you'll probably come across one or two occasions where it may miss something. Tune as you run with it!

Answer 6

My previous regex seemed to work in the tester but not in actual PHP. I have edited this answer to provide full, working PHP code, and an improved regex.

$string = 'A simple test!';
var_dump(get_first_sentence($string));

$string = 'A simple test without a character to end the sentence';
var_dump(get_first_sentence($string));

$string = '... But what about me?';
var_dump(get_first_sentence($string));

$string = 'We at StackOverflow.com prefer prices below US$ 7.50. Really, we do.';
var_dump(get_first_sentence($string));

$string = 'This will probably break after this pause .... or won\'t it?';
var_dump(get_first_sentence($string));

function get_first_sentence($string) {
    $array = preg_split('/(^.*\w+.*[\.\?!][\s])/', $string, -1, PREG_SPLIT_DELIM_CAPTURE);
    // You might want to count() but I chose not to, just add   
    return trim($array[0] . $array[1]);
}

Answer 7

This is a genuinely hard problem. I recommend looking into an NLP package if you require robust results. A tokenizer can identify sentence ending characters (either "?", ".", ";" etc depending on your intended use), and you can split on that.