# Arrays with recursion

Tell us what’s happening:

Hi Guys…

I’m not sure why, but this one is really killing me…

The concept of recursion i find a bit crazy but I’m ok with…

For me, it’s just getting the set up for the question -

“ However, notice that `multiply(arr, n) == multiply(arr, n - 1) * arr[n - 1]` .”

Am I being super dense to not get this??

Sorry/thanks

``````
function sum(arr, n) {
// Only change code below this line

// Only change code above this line
}

``````

User Agent is: `Mozilla/5.0 (iPhone; CPU iPhone OS 13_5_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/13.1.1 Mobile/15E148 Safari/604.1`.

Challenge: Replace Loops using Recursion

Put in words,

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

means

{The product of the first `n` elements in `arr`} is the same as {the product of the first `n - 1` elements in `arr`} multiplied by {the `n`th element in `arr`}

I am sure that can be clearer, but does that help somewhat?

Thanks, I’ve got it…

Not sure I could ever get that while under pressure in a real job scenario though.

Much appreciated

Help is what we’re here for. With practice I’m sure you will be able to see stuff like this easier!