php获取中文拼音首字母类和函数分享

一、公司同事整理的类,挺实用的.相信拿出来分享下他不会介意的O(∩_∩)O.不过如果首字母是数字或英文会有些问题.
代码如下:
/**
 * Helper_Spell 汉字拼音首字母工具类
 *
 * @category Helper
 * @package  Helper_Spell
 * @author   Lancer <lancer.he@gmail.com>
 * @version  1.0
 * @see      Translation_Big2gb
 */

class Helper_Spell {
/**
 * $_pinyins
 * @var array
 * @access private
 */
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',
);

/**
 * $_charset
 * @var string
 * @access private
 */
private $_charset = null;

/**
 * __construct 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 = 'utf-8' ) {
    $this->_charset = $charset;
}

/**
 * getInitialsFirst 返回首个汉字的拼音
 *
 * @access public
 * @static
 * @param  string $str
 * @return string
 * @example Helper_Spell::getInitialsFirst('我的爱'); => w
 */
public static function getInitialsFirst( $str, $charset = 'utf-8' ) {
    $chars = array(
        'A','B','C','D','E','F',
        'G','H','I','J','K','L',
        'M','N','O','P','Q','R',
        'S','T','U','V','W','X',
        'Y','Z');

    $string = self::getInitials( $str );
    $length = strlen($string);

    for($i=0; $i < $length; $i++) {
        if ( in_array( $string{$i}, $chars ) ) {
            return $string{$i};