Two Sum LeetCode 1

1/**
2 * @param {number[]} nums
3 * @param {number} target
4 * @return {number[]}
5 */
6var twoSum = function (nums, target) {
7    const seen = new Map()
8    for (let i = 0; i < nums.length; i++) {
9        if (seen.has(target - nums[i])) {
10            return [i, seen.get(target - nums[i])]
11        } else {
12            seen.set(nums[i], i)
13        }
14    }
15
16};