https://leetcode.com/problems/product-of-array-except-self/

productOfArrayExceptSelf.js

/**
 * @param {number[]} nums
 * @return {number[]}
 */
var productExceptSelf = function(nums) {

    const left = new Array(nums.length).fill(1);

    for(let i=1; i<nums.length; i++){
        left[i] = left[i-1]*nums[i-1];
    }

    let multiplier = nums[nums.length-1];
    for(let i=nums.length-2; i>=0; i--){
        left[i] = left[i] * multiplier;
        multiplier *= nums[i];
    }

    return left;
};