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揭秘：如何利用正则表达式切分字符串

最新推荐文章于 2025-04-17 08:29:04 发布

weixin_33859231

最新推荐文章于 2025-04-17 08:29:04 发布

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CC 4.0 BY-SA版权

原文链接：http://www.cnblogs.com/blts/p/5166760.html

$string1 = "你是我的上帝上帝上帝上帝上帝";

function cut_str($string, $sublen, $start = 0, $charset = 'UTF-8') {
    if ($charset == 'UTF-8') {
        $pa = "/[\x01-\x7f]|[\xc2-\xdf][\x80-\xbf]|\xe0[\xa0-\xbf][\x80-\xbf]|[\xe1-\xef][\x80-\xbf][\x80-\xbf]|\xf0[\x90-\xbf][\x80-\xbf][\x80-\xbf]|[\xf1-\xf7][\x80-\xbf][\x80-\xbf][\x80-\xbf]/";
        preg_match_all($pa, $string, $t_string);

        if (count($t_string[0]) - $start > $sublen)
            return join('', array_slice($t_string[0], $start, $sublen)) . "...";
        return join('', array_slice($t_string[0], $start, $sublen));
    }
    else {
        $start = $start * 2;
        $sublen = $sublen * 2;
        $strlen = strlen($string);
        $tmpstr = '';

        for ($i = 0; $i < $strlen; $i++) {
            if ($i >= $start && $i < ($start + $sublen)) {
                if (ord(substr($string, $i, 1)) > 129) {
                    $tmpstr.= substr($string, $i, 2);
                } else {
                    $tmpstr.= substr($string, $i, 1);
                }
            }
            if (ord(substr($string, $i, 1)) > 129)
                $i++;
        }
        if (strlen($tmpstr) < $strlen)
            $tmpstr.= "...";
        return $tmpstr;
    }
}

echo cut_str($string1, 10);