# Simple Shoppingcart Function Uisng Javascript

Thu Jul 08 2021 08:20:50 GMT+0000 (UTC)

```/*
You are developing an ecommerce application which allows users to add items to a virtual shopping cart. Once the user is done shopping, we will need to know the total amount of money to charge the user based on what was purchased.
*/

// The cart array stores all of the items selected in the shopping cart

let cart = [];

// The quantity array stores the quantity of the items in the cart.
// The cart and quantity arrays are connected based on the index i.e
// given cart = ["bread", "apple"] and quantity = [2, 1]
// we can tell that we have two pieces of bread and 1 apple.
// The item at index 0 in cart i.e cart[0] is "bread", so we get the quantity
// at the same index in the quantity array i.e quantity[0]

let quantity = [];

// The prices multidimensional array stores the prices of the items in the
// store. There are 6 items that can be purchased from the store:
// "bread", "apple", "noodles", "beef", "milk" and "coke".
// The price for "bread" is 20, the price for "apple" is 50 and so on.

const prices = [
["apple", 50],
["noodles", 100],
["beef", 40],
["milk", 32],
["coke", 25],
];

// Given an item, Complete the code to add the item to the cart and quantity
// arrays.
// Don't touch this section, we will cover functions later.
// item is a variable that represents the item that is being added to the
// cart. Valid items are items present in the prices array i.e "bread",
// "apple", "noodles", "beef", "milk" and "coke".
// An invalid item e.g "rice"  should throw an error ‘item not recognized’

let isValidItem = false;
// TODO(1): Write code to set isValidItem to true if item is present in the prices array
for(let i = 0; i < prices.length; i++){
if(item === prices[i][0]){
isValidItem = true;
}
}
// TODO(2): Throw error "item not recognized" if isValidItem !== true i.e false
if(isValidItem !== true){
throw "item not recognized"
}
let foundItem = false;
// TODO(3): Write code to check if item is in the cart array, and if so set
// foundItem = true, and increase the quantity of the item by 1
// Hint: Use the index where the item was found in the cart to increase the
// quanity in the quantity array
for(let i = 0; i < cart.length; i++){
if(item === cart[i]){
foundItem = true;
quantity[i] += 1
}
}
// TODO(4): Write code to add item to cart and set quantity to 1, if item is
// was not found in the cart i.e foundItem is not true.
// Hint: To set the quantity for the recently added item to 1,
// do quantity.push(1)
if(foundItem !== true){
cart.push(item);
quantity.push(1);
}
}

// Write the code to calculate the total cost of all items in the cart based on
// the items in the cart and the quantity of the items purchased. The total
// cost should be stored in the total variable
// Don't touch the next line, we will cover functions later.
function getTotal() {
let total = 0;

for (let i = 0; i < cart.length; i++) {
let item = cart[i];
let qty = quantity[i];
let subtotal = 0;
// TODO(7) : Loop through the prices array to get the price of item, then
// compute and set subtotal by multiplying the price and qty.
// Hint: Each array in prices has the item at index 0, and the price at
// index 1
for(let itemPrice = 0; itemPrice < prices.length; itemPrice++){
let priceList = prices[itemPrice]
let price = priceList[1];
let priceItem = priceList[0]
if(item === priceItem){
subtotal = price * qty
}
}
total += subtotal;
// TODO(8): Add subtotal to total (this should after the loop above)
}
}

// THIS IS FOR YOUR TESTING ONLY.
try {