arr = [] // empty array
const isEmpty = arr => !Array.isArray(arr) || arr.length === 0;

// Examples
isEmpty([]); // true
isEmpty([1, 2, 3]); // false

router.post("/", async (req, res) => {
	const { email, password } = req.body;

	try {
	if (!email) return res.status(400).json({ msg: "An email is required" });

	if (!password)
	return res.status(400).json({ msg: "A password is required" });

	const user = await User.findOne({ email }).select("_id password");

	if (!user) return res.status(400).json({ msg: "Invalid credentials" });

	const match = await bcrypt.compare(password, user.password);

	if (!match) return res.status(400).json({ msg: "Invalid credentials" });

	const accessToken = genAccessToken({ id: user._id });
	const refreshToken = genRefreshToken({ id: user._id });

	res.cookie("token", refreshToken, {
	expires: new Date(Date.now() + 604800),
	httpOnly: true,
	});

	res.json({ accessToken });
	} catch (err) {
	console.log(err.message);
	res.status(500).json({ msg: "Error logging in user" });
	}
});

function sortNumbers(arr) {
  return arr.slice().sort((a, b) => a - b);
}

const unsortedArray = [4, 1, 9, 6, 3, 5];

const sortedArray = sortNumbers(unsortedArray);

console.log("Unsorted Numbers:", unsortedArray);
console.log("\n");
console.log("Sorted Numbers:", sortedArray);

const arithmeticProgression  = (n, lim) =>
  Array.from({ length: Math.ceil(lim / n) }, (_, i) => (i + 1) * n );
  
arithmeticProgression(5, 25); // [5, 10, 15, 20, 25]

let nums = [1,2,3,1]

var containsDuplicate = function(nums) {
    let obj = {};
    for(let i =0; i< nums.length; i++){
        if(obj[nums[i]]){
            obj[nums[i]] += 1;
            return true;
        }else{
            obj[nums[i]] = 1;
        }
    }
    return false;
};

console.log(containsDuplicate(nums));

const hammingDistance = (num1, num2) =>
  ((num1 ^ num2).toString(2).match(/1/g) || '').length;
  
hammingDistance(2, 3); // 1