Function canSwap

javascript/0041-first-missing-positive.js:42–43

(nums, num, indexNum)

};

const canSwap = (nums, num, indexNum) =>
    isPositive(num) && isInBound(num, nums) && !isEqual(num, indexNum);

const swap = (nums, index, indexKey) =>
    ([nums[index], nums[indexKey]] = [nums[indexKey], nums[index]]);