Hi,

You should also have a line like;

let values = [1, 3, 5, 7, 9, 11, 13, 15] ← (will have different values in here.)

So, in setting up the loop, we have;

let i = values.length - 2;

This means the iterator we’re using, i, is going to us the length of the values array, minus 2 as a starting point.

So, in the case of the example above, values has 8 items in it - so that’s its length.

We take 2 off that, so i begins the loop with a value of 6.

i >= 0;

Means we’ll keep looping whilst i is greater than or equal to 0. This is checked at the end of each loop, and we’ll only start a new one if it’s true, otherwise we’ll go on to the next piece of code.

i -= 2

How much we’re changing the iterator with each loop. So, in this case we’re actually subtracting 2 from it each time.

So, for i above, it would start at 6, as described above. Then each time it looped it would minus 2 until it was no longer greater than or equal to 0;

so,

6 then 4 then 2 then 0, then it would stop as i = -2 no longer satisfies the requirement.

Now, inside your loop you have

let a = values[i];

It’s giving a the value that is at index i of the array values.

So, for the example above;

if i is 6, then values[i] would be 13.

Then as we loop through,

i = 4, values[i] = 9,

i = 2, values[i] = 5,

i = 0, values[i] = 1

It’s then using this value for a when making the calculations with total

So,

total = total / a

then

total = total + 10

Hope this helps