08年写的一个获取首字母的程序 ， 有网友写邮件提到程序bug的问题， 抽了点时间看了一下，把bug给修正了一下

/**

* created by wangbinandi@gmail.com at 2008-12-29 21:12

* 汉字拼音首字母工具类

* 注： 英文的字串：不变返回(包括数字) eg .abc123 => abc123

* 中文字符串：返回拼音首字符 eg. 王小明 => WXM

* 中英混合串: 返回拼音首字符和英文 eg. 我i我j => WIWJ

* eg.

* $py = new PYInitials();

* $result = $py->getInitials('王小明');

*/

class PYInitials

{

private $_pinyins = array(

176161 => 'A',

176197 => 'B',

178193 => 'C',

180238 => 'D',

182234 => 'E',

183162 => 'F',

184193 => 'G',

185254 => 'H',

187247 => 'J',

191166 => 'K',

192172 => 'L',

194232 => 'M',

196195 => 'N',

197182 => 'O',

197190 => 'P',

198218 => 'Q',

200187 => 'R',

200246 => 'S',

203250 => 'T',

205218 => 'W',

206244 => 'X',

209185 => 'Y',

212209 => 'Z',

215249 => 'Z',

);

private $_charset = null;

/**

* 构造函数, 指定需要的编码 default: utf-8

* 支持utf-8, gb2312

*

* @param unknown_type $charset

*/

public function __construct( $charset = 'gb2312' )

{

$this->_charset = $charset;

}

/**

* 中文字符串 substr

*

* @param string $str

* @param int $start

* @param int $len

* @return string

*/

private function _msubstr ($str, $start, $len)

{

$start = $start * 2;

$len = $len * 2;

$strlen = strlen($str);

$result = '';

for ( $i = 0; $i < $strlen; $i++ ) {

if ( $i >= $start && $i < ($start + $len) ) {

if ( ord(substr($str, $i, 1)) > 129 ) $result .= substr($str, $i, 2);

else $result .= substr($str, $i, 1);

}

if ( ord(substr($str, $i, 1)) > 129 ) $i++;

}

return $result;

}

/**

* 字符串切分为数组 (汉字或者一个字符为单位)

*

* @param string $str

* @return array

*/

private function _cutWord( $str )

{

$words = array();

while ( $str != "" )

{

if ( $this->_isAscii($str) ) {//非中文

$words[] = $str[0];

$str = substr( $str, strlen($str[0]) );

}else{

$word = $this->_msubstr( $str, 0, 1 );

$words[] = $word;

$str = substr( $str, strlen($word) );

}

}

return $words;

}

/**

* 判断字符是否是ascii字符

*

* @param string $char

* @return bool

*/

private function _isAscii( $char )

{

return ( ord( substr($char,0,1) ) < 160 );

}

/**

* 判断字符串前3个字符是否是ascii字符

*

* @param string $str

* @return bool

*/

private function _isAsciis( $str )

{

$len = strlen($str) >= 3 ? 3: 2;

$chars = array();

for( $i = 1; $i < $len -1; $i++ ){

$chars[] = $this->_isAscii( $str[$i] ) ? 'yes':'no';

}

$result = array_count_values( $chars );

if ( empty($result['no']) ){

return true;

}

return false;

}

/**

* 获取中文字串的拼音首字符

*

* @param string $str

* @return string

*/

public function getInitials( $str )

{

if ( empty($str) ) return '';

if ( $this->_isAscii($str[0]) && $this->_isAsciis( $str )){

return $str;

}

$result = array();

if ( $this->_charset == 'utf-8' ){

$str = iconv( 'utf-8', 'gb2312', $str );

}

$words = $this->_cutWord( $str );

foreach ( $words as $word )

{

if ( $this->_isAscii($word) ) {//非中文

$result[] = $word;

continue;

}

$code = ( ord(substr($word,0,1)) ) * 1000 + (ord(substr($word,1,1)));

//获取拼音首字母A--Z

if ( ($i = $this->_search($code)) != -1 ){

$result[] = $this->_pinyins[$i];

}

}

return strtoupper(implode('',$result));

}

private function _getChar( $ascii )

{

if ( $ascii >= 48 && $ascii <= 57){

return chr($ascii); //数字

}elseif ( $ascii>=65 && $ascii<=90 ){

return chr($ascii); // A--Z

}elseif ($ascii>=97 && $ascii<=122){

return chr($ascii-32); // a--z

}else{

return '~'; //其他

}

}

/**

* 查找需要的汉字内码(gb2312) 对应的拼音字符( 二分法 )

*

* @param int $code

* @return int

*/

private function _search( $code )

{

$data = array_keys($this->_pinyins);

$lower = 0;

$upper = sizeof($data)-1;

// 排除非一级汉字

if ($code < $data[0] || $code > $data[23]) return -1;

for (;;) {

if ( $lower > $upper ){

return $data[$lower-1];

}

$middle = (int) round(($lower + $upper) / 2);

if ( !isset($data[$middle]) ) {

return -1;

}

if ( $data[$middle] < $code ){

$lower = (int)$middle + 1;

}else if ( $data[$middle] == $code ) {

return $data[$middle];

}else{

$upper = (int)$middle - 1;

}

}// end for

}

}

?>