Efficient JavaScript solution
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 []
/**
 * @param {Array} arr
 * @param {Function} fn
 * @return {Array}
 */
var sortBy = function(arr, fn) {
     arr.sort((a, b) => fn(a) - fn(b))
    return arr;
};
```
['JavaScript']