# JS Help: Explanation please [spoiler]

function multiplyAll(arr){

var product=1

for (var i=0;i<arr.length;i++){
for (var j=0;j<arr[i].length;j++){
product=arr[i][j]*
}
}

return product
}

var product=multiplyAll([[1, 2], [3, 4], [5, 6, 7]])

console.log(product)

Could somebody please explain to me what is going on in the italicized statement(product*=arr[i][j])?

Can you please use the `</>` button or put three backticks ````` on new lines before and after your block of code so that we can see it?

You have an array of arrays. The line `product *= arr[i][j]` multiplies the current value of the product by the next entry in your array of arrays, specifically the `i,j` entry.

You have an array called `arr`. `arr = ([[1, 2], [3, 4], [5, 6, 7]])`, so it is an array with sub-arrays.
Let’s say `i=0` and `j=0` for this example.
`arr[i]` is `arr` which means the value at index 0 of `arr`. That value is `[1, 2]`.
`arr[i][j]` is `arr` which means the value of index 0 at index 0 of `arr`. That value is `1`.

Thank-you for helping me. So, the product is being multiplied by the the array j (index), and array i (counts the number of arrays). But if the array is being multiplied by the array, how does that work? The console would show up as NaN. Please explain further. OHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH. Welp, I’m dumb. Thanks a bunch 