Javascript中将UTF8 Fancytext转换为字母数字

function convertFancytextToAlphanumeric(fancytext) {
  var alphanumeric = "";
  for (var i = 0; i < fancytext.length; i++) {
    var unicode = fancytext.charCodeAt(i);
    if (unicode >= 65 && unicode <= 90) {
      // Convert uppercase letters
      alphanumeric += String.fromCharCode(unicode - 65 + 10);
    } else if (unicode >= 97 && unicode <= 122) {
      // Convert lowercase letters
      alphanumeric += String.fromCharCode(unicode - 97 + 36);
    } else if (unicode >= 48 && unicode <= 57) {
      // Convert digits
      alphanumeric += String.fromCharCode(unicode - 48);
    } else {
      // Ignore other characters
    }
  }
  return alphanumeric;
}

var fancytext = "𝔸𝔹𝕔𝔻𝔼𝔽𝔾ℍ𝕀𝕁𝕂𝕃𝕄ℕ𝕆ℙℚℝ𝕊𝕋𝕌𝕍𝕎𝕏𝕐ℤ";
var alphanumeric = convertFancytextToAlphanumeric(fancytext);
console.log(alphanumeric); // Output: "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"