php - 不正确的字符集

Answer 1

That is because you have Unicode characters and you are subtracting exactly in a wrong place and that letter cannot be rendered anymore.

Instead you should subtract by spaces, eg:

echo implode(' ', array_slice(explode(' ', strip_tags(html_entity_decode($sentence, ENT_QUOTES, 'UTF-8'))), 0, 50)); // for 50 words

or use substr_unicode:

function substr_unicode($str, $s, $l = null) {
    return join("", array_slice(
        preg_split("//u", $str, -1, PREG_SPLIT_NO_EMPTY), $s, $l));
}