Autotrim article body text

[haydndup]

I have a news section on the website that I am currently designing. I was hoping someone could give some advice on writing a function that will take text and trim it down to about 20 words... Basically giving a summary on each news item. I would then have a link to view the full article.

Thanks in advance.

[KrisNz]

Heres how I did it, I dont know how efficent it is but hey, it works.
[code]
$string = "here is a string that has a few words in it and is fairly long and boring and needs to be trimmed
down so that it doesnt keep going and going and going and going";
$a = explode(" ",$string,21);
array_pop($a);
$output = implode(" ",$a);
echo $output;
[/code]