Write a Program to Form Smallest Number From Two Digit Arrays

# 2605. Form Smallest Number From Two Digit Arrays

Given two arrays of unique digits nums1 and nums2, return the smallest number that contains at least one digit from each array.

### Example 1:
```
Input: nums1 = [4,1,3], nums2 = [5,7]
Output: 15
Explanation: The number 15 contains the digit 1 from nums1 and the digit 5 from nums2. It can be proven that 15 is the smallest number we can have.
```

### Example 2:
```
Input: nums1 = [3,5,2,6], nums2 = [3,1,7]
Output: 3
Explanation: The number 3 contains the digit 3 which exists in both arrays.
 ```

Constraints:
```
1 <= nums1.length, nums2.length <= 9
1 <= nums1[i], nums2[i] <= 9
All digits in each array are unique.
```

/**
 * @param {number[]} nums1
 * @param {number[]} nums2
 * @return {number}
 */
var minNumber = function(nums1, nums2) {
    const intersect = nums2.map((x) => nums1.filter((y) => y == x)).flat();
    if (intersect.length > 0) return Math.min(...intersect);

    let min1 = Math.min(...nums1), min2 = Math.min(...nums2);
    return min1 < min2 ? `${min1}${min2}` : `${min2}${min1}`;
};