how to truncate strings at the end of a sentence or word

Question

I want to use part of a blog post as the introduction to the post and then add a "read more" link at the end, but I couldn't find a way to round up the text either at the end of a word or sentence. The code below runs into an empty infinite loop.

<?php

$num_of_words = 400;
while (! substr($article, $num_of_words, 1) != "")
     $num_of_words++;

?>

Any help please? Thanks

possible duplicate of [How to Truncate a string in PHP to the word closest to a certain number of characters?](http://stackoverflow.com/questions/79960/how-to-truncate-a-string-in-php-to-the-word-closest-to-a-certain-number-of-charac) — Felix Kling, Feb 01 '11 at 14:58
"If not substring is not something".. Double negation?! Having readable code must be really low-priority in your code — ThiefMaster, Feb 01 '11 at 15:18

score 1 · Answer 1 · answered Feb 01 '11 at 15:39

1

Another way to do it would be something like this:

if (strlen($article) <= 400)
    $intro = $article;
else
    $intro = substr($article, 0, strrpos($article, ' ', strlen($article)-400));

answered Feb 01 '11 at 15:39

MarioVW

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MarioVW · Answer 2 · 2011-02-01T15:14:08.227

0

You can use regular expressions, if you want to get the first 25 words you could use something like

^([\w,\.:;]+\s+){1,25}

If you need more help with regular expressions just ask...

edited Feb 01 '11 at 15:14

answered Feb 01 '11 at 15:03

MarioVW

2,225
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This would match the first 25 **word characters**, *not* words. – Felix Kling Feb 01 '11 at 15:04
@Felix Kling: fixed the regex due to your observation – MarioVW Feb 01 '11 at 15:15
I wonder if the author didn't actually mean length < 400 (and not number of words, despite the variable). – Déjà vu Feb 01 '11 at 15:48

score 0 · Answer 3 · answered Feb 01 '11 at 15:21

0

<?php

$num_of_words = 400;

$art=explode(' ',$article);
$shortened='';
for ($i=0 ; $i<=$num_of_words ; $i++){
    $shortened.=$art[$i].' ';
}
echo $shortened;
?>

this will print out the first 400 WORDS ...

answered Feb 01 '11 at 15:21

Rami Dabain

4,709
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score 0 · Accepted Answer · answered Feb 01 '11 at 15:22

Assuming that there is a max length you don't want to exceed even if there is no whitespace, something like this would work:

$maxlength=100; //100 characters
$mystring='I want to use part of a blog post as the introduction to the post and then add a "read more" link at the end, but I couldn't find a way to round up the text either at the end of a word or sentence. The code below runs into an empty infinite loop.';

$mystring=substr($mystring,0,$maxlength); //now string can't be too long
$last_space=strrpos($mystring,' ');
$mystring=substr($mystring,-,$last_space);

But if you really want to do it by word count, keeping in mind that words can be very long, a regex like this should match up to the 1st 25 words.

/^(\w+\b){1,25}/

how to truncate strings at the end of a sentence or word

4 Answers4