JavaScript计算字符串实际长度（含中英文）的三种实现方式

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
  <script>
    /**
     * 获取字符串实际长度(包含中英文)
     * @param str  要获得长度的字符串
     */
    var zfc = {};
    zfc.getStringLength = function (str) {
      var realLength = 0, len = str.length, charCode = -1;
      for (var i = 0; i < len; i++) {
        charCode = str.charCodeAt(i);
        if (charCode >= 0 && charCode <= 128)
          realLength += 1;
        else
          realLength += 2;
      }
      return realLength;
    };
    console.log(zfc.getStringLength('aaa获取字符sfdsf串实际长度(包含中英文)sdfdsf'))
  </script>
</head>
<body>
 
</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
  <script>
    /**
     * 获取字符串实际长度(包含中英文)
     * @param str  要获得长度的字符串
     */
    var zfc = {};
    zfc.getStringLength = function (str) {
      var len = str.length;
      var realLength = 0;
      for (var i = 0; i < len; i++) {
        if ((str.charCodeAt(i) & 0xff00) != 0) {
          realLength++;
        }
        realLength++;
      }
      return realLength;
    };
    console.log(zfc.getStringLength('aaa获取字符sfdsf串实际长度(包含中英文)sdfdsf'))
  </script>
</head>
<body>
 
</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
  <script>
    /**
     * 获取字符串实际长度(包含中英文)
     * @param str  要获得长度的字符串
     */
    var zfc = {};
    zfc.getStringLength = function (str) {
      return str.replace(/[\u0391-\uFFE5]/g, 'aa').length;
    };
    console.log(zfc.getStringLength('aaa获取字符sfdsf串实际长度(包含中英文)sdfdsf'))
  </script>
</head>
<body>
 
</body>
</html>