js身份证号码升位

function upgradeIDCard(idCard15) {
    if (idCard15.length !== 15) {
        return 'Invalid ID card number';
    }

    // 将15位身份证号码扩展为17位
    let idCard17 = idCard15.substring(0, 6) + '19' + idCard15.substring(6);

    // 计算校验码
    const weights = [7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2];
    const checkCodes = ['1', '0', 'X', '9', '8', '7', '6', '5', '4', '3', '2'];

    let sum = 0;
    for (let i = 0; i < 17; i++) {
        sum += parseInt(idCard17[i]) * weights[i];
    }

    let mod = sum % 11;
    let checkCode = checkCodes[mod];

    // 返回18位身份证号码
    return idCard17 + checkCode;
}

// 示例
console.log(upgradeIDCard('110105820101001')); // 输出: 11010519820101001X