PHP implements length judgment and interception methods for Chinese and English mixed strings

This article mainly introduces PHP's methods for judging and intercepting the length of mixed Chinese and English strings. It analyzes the traversal, conversion, interception, calculation and other related operation skills of Chinese and English strings in PHP in the form of examples. Friends in need can refer to it. Next

The example in this article describes PHP's method of judging and intercepting the length of mixed Chinese and English strings. Share it with everyone for your reference, the details are as follows:

/**
 * 
 * 中英混合字符串长度判断 
 * @param unknown_type $str
 * @param unknown_type $charset
 */
function strLength($str, $charset = 'utf-8') {
  if ($charset == 'utf-8')
    $str = iconv ( 'utf-8', 'gb2312', $str );
  $num = strlen ( $str );
  $cnNum = 0;
  for($i = 0; $i < $num; $i ++) {
    if (ord ( substr ( $str, $i + 1, 1 ) ) > 127) {
      $cnNum ++;
      $i ++;
    }
  }
  $enNum = $num - ($cnNum * 2);
  $number = ($enNum / 2) + $cnNum;
  return ceil ( $number );
}

/**
 * 
 * 中英混合的字符串截取
 * @param unknown_type $sourcestr
 * @param unknown_type $cutlength
 */
function cut_str($sourcestr, $cutlength) {
  $returnstr = '';
  $i = 0;
  $n = 0;
  $str_length = strlen ( $sourcestr ); //字符串的字节数 
  while ( ($n < $cutlength) and ($i <= $str_length) ) {
    $temp_str = substr ( $sourcestr, $i, 1 );
    $ascnum = Ord ( $temp_str ); //得到字符串中第$i位字符的ascii码 
    if ($ascnum >= 224) //如果ASCII位高与224，
    {
      $returnstr = $returnstr . substr ( $sourcestr, $i, 3 ); //根据UTF-8编码规范，将3个连续的字符计为单个字符   
      $i = $i + 3; //实际Byte计为3
      $n ++; //字串长度计1
    } elseif ($ascnum >= 192) //如果ASCII位高与192，
    {
      $returnstr = $returnstr . substr ( $sourcestr, $i, 2 ); //根据UTF-8编码规范，将2个连续的字符计为单个字符 
      $i = $i + 2; //实际Byte计为2
      $n ++; //字串长度计1
    } elseif ($ascnum >= 65 && $ascnum <= 90) //如果是大写字母，
    {
      $returnstr = $returnstr . substr ( $sourcestr, $i, 1 );
      $i = $i + 1; //实际的Byte数仍计1个
      $n ++; //但考虑整体美观，大写字母计成一个高位字符
    } else //其他情况下，包括小写字母和半角标点符号，
    {
      $returnstr = $returnstr . substr ( $sourcestr, $i, 1 );
      $i = $i + 1; //实际的Byte数计1个
      $n = $n + 0.5; //小写字母和半角标点等与半个高位字符宽...
    }
  }
  if ($str_length > $cutlength) {
    $returnstr = $returnstr . "..."; //超过长度时在尾处加上省略号
  }
  return $returnstr;
}

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