<?php/** * 將十進制數字轉換為二十六進制字母串 */function num2alpha($intNum, $isLower=true){  $num26 = base_convert($intNum, 10, 26);  $addcode = $isLower ? 49 : 17;  $result = '';  for ($i=0; $i<strlen($num26); $i++) {    $code = ord($num26{$i});    if ($code < 58) {      $result .= chr($code+$addcode);    } else {      $result .= chr($code+$addcode-39);    }  }  return $result;}/** * 將二十六進制字母串轉換為十進制數字 */function alpha2num($strAlpha){  if (ord($strAlpha{0}) > 90) {    $startCode = 97;    $reduceCode = 10;  } else {    $startCode = 65;    $reduceCode = -22;  }  $num26 = '';  for ($i=0; $i<strlen($strAlpha); $i++) {    $code = ord($strAlpha{$i});    if ($code < $startCode+10) {      $num26 .= $code-$startCode;    } else {      $num26 .= chr($code-$reduceCode);    }  }  return (int)base_convert($num26, 26, 10);}