Array Reduce Transformation 
IntuitionApproachComplexity
Time complexity:

Space complexity:
Code
# Intuition
<!-- Describe your first thoughts on how to solve this problem. -->

# Approach
<!-- Describe your approach to solving the problem. -->

# Complexity
- Time complexity:
<!-- Add your time complexity here, e.g. $$O(n)$$ -->

- Space complexity:
<!-- Add your space complexity here, e.g. $$O(n)$$ -->

# Code
```javascript []
var reduce = function(nums, fn, init) {
     let val = init;
  for (let i = 0; i < nums.length; i++) {
    val = fn(val, nums[i]);
  }
  return val;
};
```
['JavaScript']