PHP转换ASCII码的类文件，通过此类方便的转换PHP为Ascii码，经测试无错可用，将以上代码复制粘贴保存为ascii_class.php。下面与大家分享这个类的代码：
<?php
class ascii
{
function decode($str)
{
preg_match_all( "/(d{2,5})/", $str,$a);
$a = $a[0];
foreach ($a as $dec)
{
if ($dec < 128)
{
$utf .= chr($dec);
}
else if ($dec < 2048)
{
$utf .= chr(192 + (($dec - ($dec % 64)) / 64));
$utf .= chr(128 + ($dec % 64));
}
else
{
$utf .= chr(224 + (($dec - ($dec % 4096)) / 4096));
$utf .= chr(128 + ((($dec % 4096) - ($dec % 64)) / 64));
$utf .= chr(128 + ($dec % 64));
}
}
return $utf;
}
function encode($c)
{
$len = strlen($c);
$a = 0;
while ($a < $len)
{
$ud = 0;
if (ord($c{$a}) >=0 && ord($c{$a})<=127)
{
$ud = ord($c{$a});
$a += 1;
}
else if (ord($c{$a}) >=192 && ord($c{$a})<=223)
{
$ud = (ord($c{$a})-192)*64 + (ord($c{$a+1})-128);
$a += 2;
}
else if (ord($c{$a}) >=224 && ord($c{$a})<=239)
{
$ud = (ord($c{$a})-224)*4096 + (ord($c{$a+1})-128)*64 + (ord($c{$a+2})-128);
$a += 3;
}
else if (ord($c{$a}) >=240 && ord($c{$a})<=247)
{
$ud = (ord($c{$a})-240)*262144 + (ord($c{$a+1})-128)*4096 + (ord($c{$a+2})-128)*64 + (ord($c{$a+3})-128);
$a += 4;
}
else if (ord($c{$a}) >=248 && ord($c{$a})<=251)
{
$ud = (ord($c{$a})-248)*16777216 + (ord($c{$a+1})-128)*262144 + (ord($c{$a+2})-128)*4096 + (ord($c{$a+3})-128)*64 + (ord($c{$a+4})-128);
$a += 5;
}
else if (ord($c{$a}) >=252 && ord($c{$a})<=253)
{
$ud = (ord($c{$a})-252)*1073741824 + (ord($c{$a+1})-128)*16777216 + (ord($c{$a+2})-128)*262144 + (ord($c{$a+3})-128)*4096 + (ord($c{$a+4})-128)*64 + (ord($c{$a+5})-128);
$a += 6;
}
else if (ord($c{$a}) >=254 && ord($c{$a})<=255)
{ //error
$ud = false;
}
$scill .= "&#$ud;";
}
return $scill;
}
}
?>调用方法：
require_once "ascii_class.php";//引入类文件
$aa = new ascii;//建立对象
echo $aa -> encode("a");//a为待转换的PHP字符