如何在PHP中将字符串截断为前n个单词

Question

I would like to truncate a very long string, formatted via html elements.

I need the first 500 words (somehow I have to avoid html tags <p>, <br> while my function truncating the string), but in the result I have to keep/use those html elements because the result also should be formatted by html tags like the "original whole" text.

What's the best way to truncate my string?

Example:

Original text

> <p><a href="/t/the-huffington-post">The Huffington Post</a> (via <a
> href="/t/daily-mail">Daily Mail</a>) is reporting that <a
> href="/t/misty">Misty</a> has been returned to a high kill shelter for
> farting too much! She appeared on Greenville County Pet Rescue’s
> “urgent” list, which means if she doesn’t get readopted, she will be
> euthanized!</p>

I need the first n words (n=10)

>  <p><a href="/t/the-huffington-post">The Huffington Post</a> (via <a
> href="/t/daily-mail">Daily Mail</a>) is reporting that.. </p>

Answer 1

A brute force method would be to just split all elements on blanks, then iterate over them. You count only non-tag elements up to a maximum, while you output tags nonetheless. Something along these lines:

$string = "your string here";
$output = "";
$count = 0;
$max = 10;
$tokens = preg_split('/ /', $string);
foreach ($tokens as $token)
{
  if (preg_match('/<.*?>/', $token)) {
    $output .= "$token ";
  } else if ($count < $max) {
    $output .= "$token ";
    $count += 1;
  }
}
print $output;