有谁理解编码知识，utf-8,gbk,big2,unicode 之间的转换?请高手帮忙啊
function CHSUtoUTF8($c)
{
$str='';

if ($c < 0x80)
{
$str .= $c;
}
elseif ($c < 0x800)
{
$str .= (0xC0 | $c >> 6);
$str .= (0x80 | $c & 0x3F);
}
elseif ($c < 0x10000)
{
$str .= (0xE0 | $c >> 12);
$str .= (0x80 | $c >> 6 & 0x3F);
$str .= (0x80 | $c & 0x3F);
}
elseif ($c < 0x200000)
{
$str .= (0xF0 | $c >> 18);
$str .= (0x80 | $c >> 12 & 0x3F);
$str .= (0x80 | $c >> 6 & 0x3F);
$str .= (0x80 | $c & 0x3F);
}

return $str;
}


QQ:1302781404

希望能够解决！

[解决办法]
你写的这个有问题？
[解决办法]
编码转换的过程是

1）先解码-》再用另一种方式去编码