php实现获取汉字的首字母两个实例

要获取汉字首字母的方法有很多，这个我们一般要把汉字分出来然后转换成拼音，然后再利用substr取第一个字母了，下面我网上找到两个实例，各有千秋大家一起来看看吧。

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例1

主要功能是：功能明确，易于修改维护和扩展； 英文的字串：不变返回(包括数字)；中文字符串：返回拼音首字符； 中英混合串: 返回拼音首字符和英文。该算法采用了二分法查找，修复了之前字母Z读取成Y的错误。好东西要收藏，故在此留下印记，以供后人考证！

代码如下

复制代码

/** * 修复二分法查找方法 * 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. 测试字符串 => CSZFC *      中英混合串: 返回拼音首字符和英文   eg. 我i我j => WIWJ *  eg. *  $py = new str2PY(); *  $result = $py->getInitials('啊吧才的饿飞就好i就看了吗你哦平去人是他uv我想一在'); */ class str2PY {     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',     );     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 = 'utf-8' )     {         $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             if ( $i >= $start && $i                 if ( ord(substr($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) )     }     /**      * 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             $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 && $ascii             return chr($ascii);  /*数字*/         }elseif ( $ascii>=65 && $ascii             return chr($ascii);   /* A--Z*/         }elseif ($ascii>=97 && $ascii             return chr($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;   $middle = (int) round(($lower + $upper) / 2);         if ( $code         for (;;) {             if ( $lower > $upper ){                 return $data[$lower-1];             }             $tmp = (int) round(($lower + $upper) / 2);             if ( !isset($data[$tmp]) ){     return $data[$middle];             }else{     $middle = $tmp;    }             if ( $data[$middle]                 $lower = (int)$middle + 1;             }else if ( $data[$middle] == $code ) {                 return $data[$middle];             }else{                 $upper = (int)$middle - 1;             }         }     } } ?>

例2

取汉字的asc区间然后返回汉字首字母了。

 

代码如下

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function getfirstchar($s0){        $fchar = ord($s0{0});     if($fchar >= ord("A") and $fchar     $s1 = iconv("UTF-8","gb2312", $s0);     $s2 = iconv("gb2312","UTF-8", $s1);     if($s2 == $s0){$s = $s1;}else{$s = $s0;}     $asc = ord($s{0}) * 256 + ord($s{1}) - 65536;     if($asc >= -20319 and $asc     if($asc >= -20283 and $asc     if($asc >= -19775 and $asc     if($asc >= -19218 and $asc     if($asc >= -18710 and $asc     if($asc >= -18526 and $asc     if($asc >= -18239 and $asc     if($asc >= -17922 and $asc     if($asc >= -17417 and $asc     if($asc >= -16474 and $asc     if($asc >= -16212 and $asc     if($asc >= -15640 and $asc     if($asc >= -15165 and $asc     if($asc >= -14922 and $asc     if($asc >= -14914 and $asc     if($asc >= -14630 and $asc     if($asc >= -14149 and $asc     if($asc >= -14090 and $asc     if($asc >= -13318 and $asc     if($asc >= -12838 and $asc     if($asc >= -12556 and $asc     if($asc >= -11847 and $asc     if($asc >= -11055 and $asc     return null; }     function pinyin1($zh){     $ret = "";     $s1 = iconv("UTF-8","gb2312", $zh);     $s2 = iconv("gb2312","UTF-8", $s1);     if($s2 == $zh){$zh = $s1;}     for($i = 0; $i         $s1 = substr($zh,$i,1);         $p = ord($s1);         if($p > 160){             $s2 = substr($zh,$i++,2);             $ret .= getfirstchar($s2);         }else{             $ret .= $s1;         }     }     return $ret; } echo "这是中文字符串 "; echo pinyin1('这是中文字符串');   ?>