✅EASY JAVASCRIPT SOLUTION
Intuition\n Describe your first thoughts on how to solve this problem. \n\n# Approach\n Describe your approach to solving the problem. \n\n# Complexity\n- Time 
# Intuition\n<!-- Describe your first thoughts on how to solve this problem. -->\n\n# Approach\n<!-- Describe your approach to solving the problem. -->\n\n# Complexity\n- Time complexity:\n<!-- Add your time complexity here, e.g. $$O(n)$$ -->\n\n- Space complexity:\n<!-- Add your space complexity here, e.g. $$O(n)$$ -->\n\n# Code\n![Upvote.png](https://assets.leetcode.com/users/images/70fb5c69-5be7-47eb-a055-9c6330448b21_1723447539.762153.png)\n\n```\n/**\n * @param {number[]} nums\n * @param {Function} fn\n * @param {number} init\n * @return {number}\n */\nvar reduce = function(nums, fn, init) {\n     let val = init;\n  for (let i = 0; i < nums.length; i++) {\n    val = fn(val, nums[i]);\n  }\n  return val;\n};\n```
['JavaScript']