php取得字符串首字母的方法


            本文实例讲述了php取得字符串首字母的方法。分享给大家供大家参考。具体实现方法如下：





<?php

$limit = array( //gb2312 拼音排序

  array(45217,45252), //A

  array(45253,45760), //B

  array(45761,46317), //C

  array(46318,46825), //D

  array(46826,47009), //E

  array(47010,47296), //F

  array(47297,47613), //G

  array(47614,48118), //H

  array(0,0),     //I

  array(48119,49061), //J

  array(49062,49323), //K

  array(49324,49895), //L

  array(49896,50370), //M

  array(50371,50613), //N

  array(50614,50621), //O

  array(50622,50905), //P

  array(50906,51386), //Q

  array(51387,51445), //R

  array(51446,52217), //S

  array(52218,52697), //T

  array(0,0),     //U

  array(0,0),     //V

  array(52698,52979), //W

  array(52980,53688), //X

  array(53689,54480), //Y

  array(54481,55289), //Z

);

$str="A:这是一个测试程序1";

$str= iconv("UTF-8","gb2312", $str);

echo $str."</br>";

$i=0;

while($i<strlen($str) ) {

  $tmp=bin2hex(substr($str,$i,1));

  if($tmp>='B0'){ //汉字的开始

    $t=getLetter(hexdec(bin2hex(substr($str,$i,2))));

    printf("%c",$t==-1 ? '*' : $t );

    $i+=2;

  }

  else{

    printf("%s",substr($str,$i,1));

    $i++;

  }

}

function getLetter($num){

  global $limit;

  $char_index=65;

  foreach($limit as $k=>$v){

    if($num>=$v[0] && $num<=$v[1]){

      $char_index+=$k;

      return $char_index;

    }

  }

  return -1;

}

?>



希望本文所述对大家的php程序设计有所帮助。