I’m currently on the Code Camp lesson for recursion, which teaches how to multiply elements within an array using recursion.

I don’t understand the logic of this statement:

`multiply(arr, n) == multiply(arr, n - 1) * arr[n - 1]`

I get the logic of how the “for” function works doing this:

```
function multiply(arr, n) {
var product = 1;
for (var i = 0; i < n; i++) {
product *= arr[i];
}
return product;
}
```

Is the “n-1” introduced because the array uses zero based indexing? So you wouldn’t multiply 0?

I’m just confused on how we came to the conclusion that

`multiply(arr, n) == multiply(arr, n - 1) * arr[n - 1]`

Thanks

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**Challenge:** Replace Loops using Recursion

**Link to the challenge:**