Node Ecommerce Cart NaN Issue - node.js

Question

Working on calculating a total for my cart which it seems that I'm running into a number issue. I'm not really sure where I am going wrong with this function. Please disregard if I haven't calculated the totals correctly as I just coded it, but with the JSON I am passing numbers and not strings.
JSON
{
"id": "611afa8b9069c9126cff3357",
"discount": {
"title": "None",
"type": "None",
"percent": 0
},
"items": [
{
"sku": 1000,
"qty": 2,
"price": 10.99
},
{
"sku": 1001,
"qty": 2,
"price": 16.99
},
{
"sku": 1003,
"qty": 1,
"price": 15.99
}
]
}
const calculateTotal = (items, discount) => {
let total = 0;
let discountAmt = 0;
console.log(discount);
console.log(items);
console.log(items.length);
for (let i = 0; (j = items.length), i < j; i++) {
discountAmt = 0;
if (discount.type == "Item" && discount.itemNum == j.sku) {
discountAmt = j.price * (discount.percent / 100);
total = total - discountAmt;
} else {
total = total + j.price * j.qty;
}
}
if (discount.type == "Order") {
discountAmt = 0;
discountAmt = total * (discount.percent / 100);
total = total - discountAmt;
}
console.log(total);
return total;
};
Console Returning
{ title: 'None', type: 'None', percent: 0 }
[
{ sku: 1000, qty: 2, price: 10.99 },
{ sku: 1001, qty: 2, price: 16.99 },
{ sku: 1003, qty: 1, price: 15.99 }
]
3
NaN
NaN

Answer 1

If you want to loop through your items, then your loop is not correct.
You can do something like this:
for (let i = 0; i < items.length; i++) { // i as index
let j = items[i]; // j will have the object based on the index
discountAmt = 0;
if (discount.type == "Item" && discount.itemNum == j.sku) {
discountAmt = j.price * (discount.percent / 100);
total = total - discountAmt;
} else {
total = total + j.price * j.qty;
}
}
or much simpler:
for (let j of items) {
discountAmt = 0;
if (discount.type == "Item" && discount.itemNum == j.sku) {
discountAmt = j.price * (discount.percent / 100);
total = total - discountAmt;
} else {
total = total + j.price * j.qty;
}
}