This is their answers based on the code below of recursion, I dont get where they got all random arrays, they don’t have one particular array in this problem. I am confuse all these arrays, dont we suppose to have just one array. Can you please help to explain how they got the answers and what happen if we pass n = 1, or 2, 3, 4, 5, 6 and so on…

`sum([1], 0)`

should equal 0.

Passed

`sum([2, 3, 4], 1)`

should equal 2.

Passed

`sum([2, 3, 4, 5], 3)`

should equal 9.

Passed

Your code should not rely on any kind of loops ( `for`

or `while`

or higher order functions such as `forEach`

, `map`

, `filter`

, or `reduce`

.).

Passed

You should use recursion to solve this problem.

**Your code so far**

```
function sum(arr, n) {
// Only change code below this line
if (n <= 0) {
return 0;
} else {
return sum(arr, n - 1) + arr[n - 1];
}
// Only change code above this line
}
sum([1], 0);
sum([1], 1);
```

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.

**Challenge:** Replace Loops using Recursion

**Link to the challenge:**