Array_Reduce_Transformation.js

/**
 * @param {number[]} nums
 * @param {Function} fn
 * @param {number} init
 * @return {number}
 */
var reduce = function(nums, fn, init) {
    if (nums.length == 0) 
    {
        return init;
    }
    let val = init;
    for (let i=0;i<nums.length;i++)
    {
        val = fn(val,nums[i]);
    }
    return val;
};