使用ASCII码格式化字符串和删除特殊字符不起作用(JavaScript)

// 格式化字符串
function formatString(str) {
  let formattedStr = "";
  for (let i = 0; i < str.length; i++) {
    const charCode = str.charCodeAt(i);
    if (charCode >= 65 && charCode <= 90) {
      formattedStr += String.fromCharCode(charCode + 32); // 将大写字母转换为小写字母
    } else {
      formattedStr += str.charAt(i);
    }
  }
  return formattedStr;
}

// 删除特殊字符
function removeSpecialCharacters(str) {
  let newStr = "";
  for (let i = 0; i < str.length; i++) {
    const charCode = str.charCodeAt(i);
    if ((charCode >= 48 && charCode <= 57) || (charCode >= 97 && charCode <= 122)) {
      newStr += str.charAt(i);
    }
  }
  return newStr;
}

// 示例用法
const inputString = "Hello!@# World";
const formattedString = formatString(inputString);
const removedSpecialCharacters = removeSpecialCharacters(inputString);

console.log(formattedString); // 输出: hello world
console.log(removedSpecialCharacters); // 输出: HelloWorld