中文汉字 转成数字 编码 方法【转】

<?php
class StrFormat_F10{
    static function encode($var){
        $ascii = '';
        $strlen_var = strlen($var);
        for ($c = 0; $c < $strlen_var; ++$c) {

            $ord_var_c = ord($var{$c});

            switch (true) {
                case $ord_var_c == 0x08:
                    $ascii .= 'b';
                    break;
                case $ord_var_c == 0x09:
                    $ascii .= 't';
                    break;
                case $ord_var_c == 0x0A:
                    $ascii .= 'n';
                    break;
                case $ord_var_c == 0x0C:
                    $ascii .= 'f';
                    break;
                case $ord_var_c == 0x0D:
                    $ascii .= 'r';
                    break;

                case $ord_var_c == 0x22:
                case $ord_var_c == 0x2F:
                case $ord_var_c == 0x5C:
                    $ascii .= '\'.$var{$c};
                    break;

                case (($ord_var_c >= 0x20) && ($ord_var_c <= 0x7F)):
                    $ascii .= $var{$c};
                    break;

                case (($ord_var_c & 0xE0) == 0xC0):
                    $char = pack('C*', $ord_var_c, ord($var{$c + 1}));
                    $c += 1;
                    $utf16 = self::utf82utf16($char);
                    $ascii .= '&#'.hexdec(bin2hex($utf16)).';';
                    break;

                case (($ord_var_c & 0xF0) == 0xE0):
                    $char = pack('C*', $ord_var_c,
                                 ord($var{$c + 1}),
                                 ord($var{$c + 2}));
                    $c += 2;
                    $utf16 = self::utf82utf16($char);
                    $ascii .= '&#'.hexdec(bin2hex($utf16)).';';
                    break;

                case (($ord_var_c & 0xF8) == 0xF0):
                    $char = pack('C*', $ord_var_c,
                                 ord($var{$c + 1}),
                                 ord($var{$c + 2}),
                                 ord($var{$c + 3}));
                    $c += 3;
                    $utf16 = self::utf82utf16($char);
                    $ascii .= '&#'.hexdec(bin2hex($utf16)).';';
                    break;

                case (($ord_var_c & 0xFC) == 0xF8):
                    $char = pack('C*', $ord_var_c,
                                 ord($var{$c + 1}),
                                 ord($var{$c + 2}),
                                 ord($var{$c + 3}),
                                 ord($var{$c + 4}));
                    $c += 4;
                    $utf16 = self::utf82utf16($char);
                    $ascii .= '&#'.hexdec(bin2hex($utf16)).';';
                    break;

                case (($ord_var_c & 0xFE) == 0xFC):
                    $char = pack('C*', $ord_var_c,
                                 ord($var{$c + 1}),
                                 ord($var{$c + 2}),
                                 ord($var{$c + 3}),
                                 ord($var{$c + 4}),
                                 ord($var{$c + 5}));
                    $c += 5;
                    $utf16 = self::utf82utf16($char);
                    $ascii .= '&#'.hexdec(bin2hex($utf16)).';';
                    break;
            }
        }

        return $ascii;
    }
    
    static function decode($var){
        $chrs = $var;
        $utf8 = '';
        $strlen_chrs = strlen($chrs);

        for ($c = 0; $c < $strlen_chrs; $c++) {

            $substr_chrs_c_2 = substr($chrs, $c, 2);
            $ord_chrs_c = ord($chrs{$c});

            switch (true) {
                case $substr_chrs_c_2 == 'b':
                    $utf8 .= chr(0x08);
                    ++$c;
                    break;
                case $substr_chrs_c_2 == 't':
                    $utf8 .= chr(0x09);
                    ++$c;
                    break;
                case $substr_chrs_c_2 == 'n':
                    $utf8 .= chr(0x0A);
                    ++$c;
                    break;
                case $substr_chrs_c_2 == 'f':
                    $utf8 .= chr(0x0C);
                    ++$c;
                    break;
                case $substr_chrs_c_2 == 'r':
                    $utf8 .= chr(0x0D);
                    ++$c;
                    break;

                case $substr_chrs_c_2 == '\"':
                case $substr_chrs_c_2 == '\'':
                case $substr_chrs_c_2 == '\\':
                case $substr_chrs_c_2 == '\/':
                    if (($delim == '"' && $substr_chrs_c_2 != '\'') ||
                       ($delim == "'" && $substr_chrs_c_2 != '\"')) {
                        $utf8 .= $chrs{++$c};
                    }
                    break;

                case preg_match('/&#[0-9]{5};/i', substr($chrs, $c, 8)):
                    $tmpstr=substr($chrs, $c, 8);
                    $tmpstr=dechex(substr($tmpstr, 2, 5));
                    $utf16 = chr(hexdec(substr($tmpstr, 0, 2)))
                           . chr(hexdec(substr($tmpstr, 2, 2)));
                    $utf8 .= self::utf162utf8($utf16);
                    $c += 7;
                    break;

                case ($ord_chrs_c >= 0x20) && ($ord_chrs_c <= 0x7F):
                    $utf8 .= $chrs{$c};
                    break;

                case ($ord_chrs_c & 0xE0) == 0xC0:
                    $utf8 .= substr($chrs, $c, 2);
                    ++$c;
                    break;

                case ($ord_chrs_c & 0xF0) == 0xE0:
                    $utf8 .= substr($chrs, $c, 3);
                    $c += 2;
                    break;

                case ($ord_chrs_c & 0xF8) == 0xF0:
                    $utf8 .= substr($chrs, $c, 4);
                    $c += 3;
                    break;

                case ($ord_chrs_c & 0xFC) == 0xF8:
                    $utf8 .= substr($chrs, $c, 5);
                    $c += 4;
                    break;

                case ($ord_chrs_c & 0xFE) == 0xFC:
                    $utf8 .= substr($chrs, $c, 6);
                    $c += 5;
                    break;

            }

        }

        return $utf8;   
    }

    static function utf82utf16($utf8){
        if(function_exists('mb_convert_encoding')) {
            return mb_convert_encoding($utf8, 'UTF-16', 'UTF-8');
        }

        switch(strlen($utf8)) {
            case 1:
                return $utf8;

            case 2:
                return chr(0x07 & (ord($utf8{0}) >> 2))
                     . chr((0xC0 & (ord($utf8{0}) << 6))
                         | (0x3F & ord($utf8{1})));

            case 3:
                return chr((0xF0 & (ord($utf8{0}) << 4))
                         | (0x0F & (ord($utf8{1}) >> 2)))
                     . chr((0xC0 & (ord($utf8{1}) << 6))
                         | (0x7F & ord($utf8{2})));
        }
        return '';
    }
    
    static function utf162utf8($utf16){
        if(function_exists('mb_convert_encoding')) {
            return mb_convert_encoding($utf16, 'UTF-8', 'UTF-16');
        }
        $bytes = (ord($utf16{0}) << 8) | ord($utf16{1});
        switch(true) {
            case ((0x7F & $bytes) == $bytes):
                return chr(0x7F & $bytes);

            case (0x07FF & $bytes) == $bytes:
                return chr(0xC0 | (($bytes >> 6) & 0x1F))
                     . chr(0x80 | ($bytes & 0x3F));

            case (0xFFFF & $bytes) == $bytes:
                return chr(0xE0 | (($bytes >> 12) & 0x0F))
                     . chr(0x80 | (($bytes >> 6) & 0x3F))
                     . chr(0x80 | ($bytes & 0x3F));
        }
        return '';
    }
}


$str = StrFormat_F10::encode("旅游");
print_r($str . "n");