sum_1d_array.js

/**
 * @param {number[]} nums
 * @return {number[]}
 */
var runningSum = function(nums) {
    let result = [];
    
    result[0] = nums[0];
    
    for(let i = 1; i < nums.length; i++)
        result.push(nums[i] + result[i-1]);
                    
    return result;
};