js 数字转字母

function numberToLetter(num) {
    if (num < 0 || num > 25) {
        throw new Error('Number out of range (0-25)');
    }
    return String.fromCharCode(65 + num); // 65是'A'的ASCII码
}

console.log(numberToLetter(0)); // 输出 'A'
console.log(numberToLetter(25)); // 输出 'Z'

function numberToLetterExtended(num) {
    if (num <= 0) {
        throw new Error('Number must be positive');
    }
    let result = '';
    while (num > 0) {
        num--; // 调整为0-25范围
        let remainder = num % 26;
        result = String.fromCharCode(65 + remainder) + result;
        num = Math.floor(num / 26);
    }
    return result;
}

console.log(numberToLetterExtended(1)); // 输出 'A'
console.log(numberToLetterExtended(26)); // 输出 'Z'
console.log(numberToLetterExtended(27)); // 输出 'AA'