contain duplicate

Link : https://neetcode.io/problems/duplicate-integer

solution 1

let nums = [1, 2, 3, 3, 5, 4, 4, 7, 9, 1];
function hasDuplicate_01(nums) {
  const x = {};
  for (let i = 0; i < nums?.length; i++) {
    if (x.hasOwnProperty(nums[i])) {
      return true;
    }
    x[nums[i]] = nums[i];
  }
  return false;
}
let res = hasDuplicate_01(nums);
console.log(res);

solution 2

let nums = [1, 2, 3, 3, 5, 4, 4, 7, 9, 1];
function hasDuplicate_02(nums) {
  const numsSet = new Set();
  for (const num of nums) {
    if (numsSet.has(num)) return true;
    numsSet.add(num);
  }
  return false;
}
let res = hasDuplicate_02(nums);
console.log(res);