PHP 中文字串截取方法匯總

PHP 截取字串代碼

通過指定編碼進行字串截取:

12345678910111213141516171819202122232425

/**　* @todo 中文截取，支援gb2312,gbk,utf-8,big5　*　* @param string $str 要截取的字串　* @param int $start 截取起始位置　* @param int $length 截取長度　* @param string $charset utf-8|gb2312|gbk|big5 編碼　* @param $suffix 是否加尾綴　*/function CsubStrPro($str, $start = 0, $length, $charset = "utf-8", $suffix = true){ if (function_exists ( "mb_substr" )) return mb_substr ( $str, $start, $length, $charset );  $re ['utf-8'] = "/[\x01-\x7f]|[\xc2-\xdf][\x80-\xbf]|[\xe0-\xef][\x80-\xbf]{2}|[\xf0-\xff][\x80-\xbf]{3}/"; $re ['gb2312'] = "/[\x01-\x7f]|[\xb0-\xf7][\xa0-\xfe]/"; $re ['gbk'] = "/[\x01-\x7f]|[\x81-\xfe][\x40-\xfe]/"; $re ['big5'] = "/[\x01-\x7f]|[\x81-\xfe]([\x40-\x7e]|\xa1-\xfe])/"; preg_match_all ( $re [$charset], $str, $match ); $slice = join ( "", array_slice ( $match [0], $start, $length ) ); if ($suffix) return $slice . "…";  return $slice;}

2：自動識別 GBK 和UTF-8 編碼的字串

1234567891011121314151617181920212223242526272829303132333435363738

function cutStr($sourcestr, $cutstart=0, $cutlength) { $returnstr = ''; $i = 0; $n = 0; $str_length = strlen ( $sourcestr ); //字串的位元組數 while ( ($n < $cutlength) and ($i <= $str_length) ) { $temp_str = substr ( $sourcestr, $i, 1 ); $ascnum = Ord ( $temp_str ); //得到字串中第$i位字元的ascii碼 if ($ascnum >= 224) //如果ASCII位高與224， { $returnstr = $returnstr . substr ( $sourcestr, $i, 3 ); //根據UTF-8編碼規範，將3個連續的字元計為單個字元 $i = $i + 3; //實際Byte計為3 $n ++; //字串長度計1 } elseif ($ascnum >= 192) //如果ASCII位高與192， { $returnstr = $returnstr . substr ( $sourcestr, $i, 2 ); //根據UTF-8編碼規範，將2個連續的字元計為單個字元 $i = $i + 2; //實際Byte計為2 $n ++; //字串長度計1 } elseif ($ascnum >= 65 && $ascnum <= 90) //如果是大寫字母， { $returnstr = $returnstr . substr ( $sourcestr, $i, 1 ); $i = $i + 1; //實際的Byte數仍計1個 $n ++; //但考慮整體美觀，大寫字母計成一個高位字元 } else //其他情況下，包括小寫字母和半形標點符號， { $returnstr = $returnstr . substr ( $sourcestr, $i, 1 ); $i = $i + 1; //實際的Byte數計1個 $n = $n + 0.5; //小寫字母和半形標點等與半個高位字元寬... } } if ($str_length > $i) { $returnstr = $returnstr . "..."; //超過長度時在尾處加上省略符號 } return $returnstr;}