OptV2.js

/* 
There is a function signFunc(x) that returns:

1 if x is positive.
-1 if x is negative.
0 if x is equal to 0.
You are given an integer array nums. Let product be the product of all values in the array nums.

Return signFunc(product).
*/
/**
 * @param {number[]} nums
 * @return {number}
 */
function signFunc(x) {
    if (x > 0) return 1;
    if (x < 0) return -1;
    return 0;
}

function arraySign(nums) {
    let product = 1;
    for (let num of nums) {
        if (num === 0) return 0; // If any number is 0, the product is 0
        product *= num;
    }
    return signFunc(product);
}

/*
Example 1:

Input: nums = [-1,-2,-3,-4,3,2,1]
Output: 1
Explanation: The product of all values in the array is 144, and signFunc(144) = 1

Example 2:

Input: nums = [1,5,0,2,-3]
Output: 0
Explanation: The product of all values in the array is 0, and signFunc(0) = 0

Example 3:

Input: nums = [-1,1,-1,1,-1]
Output: -1
Explanation: The product of all values in the array is -1, and signFunc(-1) = -1
*/