php中怎么截取中文字符串

php中如何截取中文字符串?
众所周知php原生函数substr是不支持截取中文字符串的。下面的代码提供了多种截取php中文字符串的方法。

1. 截取GB2312中文字符串

<?php < ?php//截取中文字符串function mysubstr($str, $start, $len) {    $tmpstr = "";    $strlen = $start + $len;    for($i = 0; $i < $strlen; $i++) {        if(ord(substr($str, $i, 1)) > 0xa0) {            $tmpstr .= substr($str, $i, 2);            $i++;        } else            $tmpstr .= substr($str, $i, 1);    }    return $tmpstr;}?>

2. 截取utf8编码的多字节字符串

<?php < ?php//截取utf8字符串function utf8Substr($str, $from, $len){    return preg_replace('#^(?:[\x00-\x7F]|[\xC0-\xFF][\x80-\xBF]+){0,'.$from.'}'.                       '((?:[\x00-\x7F]|[\xC0-\xFF][\x80-\xBF]+){0,'.$len.'}).*#s',                       '$1',$str);}?>

3. UTF-8、GB2312都支持的汉字截取函数

<?php < ?php/*Utf-8、gb2312都支持的汉字截取函数cut_str(字符串, 截取长度, 开始长度, 编码);编码默认为 utf-8开始长度默认为 0*/function cut_str($string, $sublen, $start = 0, $code = 'UTF-8'){    if($code == '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; $i=$start && $i129)                {                    $tmpstr.= substr($string, $i, 2);                }                else                {                    $tmpstr.= substr($string, $i, 1);                }            }            if(ord(substr($string, $i, 1))>129) $i++;        }        if(strlen($tmpstr)

4. BugFree 的字符截取函数

 * @param string  $String  the string to cut. * @param int     $Length  the length of returned string. * @param booble  $Append  whether append "...": false|true * @return string           the cutted string. */function sysSubStr($String,$Length,$Append = false){    if (strlen($String) =224 )            {                $StringTMP = substr($String,$I,3);                $I = $I + 3;            }            elseif( ord($StringTMP) >=192 )            {                $StringTMP = substr($String,$I,2);                $I = $I + 2;            }            else            {                $I = $I + 1;            }            $StringLast[] = $StringTMP;        }        $StringLast = implode("",$StringLast);        if($Append)        {            $StringLast .= "...";        }        return $StringLast;    }}$String = "17test.info 走在中国自动化测试的前沿";$Length = "18";$Append = false;echo sysSubStr($String,$Length,$Append);?>