function to check for the position of 2 numbers that equal a certain sum

gistfile1.txt

/**
 * Function to check for the position of 2 numbers that equal a certain sum. Only one pair per array.
 * @param {number[]} nums
 * @param {number} target
 * @return {number[]}
 */
const twoSum = function(nums, target) {
    let checked = {},
        found;
    nums.forEach((n, index) => {
        if (found) return;
        const complement = target - n;

        if (checked[complement]) {
            found = [checked[complement].position, index];
        }
        else {
          checked[n] = { position: index };
        }
    })
    return found;
};

const nums = [ 1, 3, 2, 9, 4, 8];
const target = 6;
const findPosition = twoSum(nums, target);
console.log(findPosition);