如何在 POST 方法中传递多个变量？

Question

I can't figure out how to pass in multiple variables in the body of the post method. What I want to achieve is passing all the itemId's for the cart to be sent to the checkout screen of my site. I'll give an example (I know the code is wrong but it shows what I want)

function purchaseClicked() {
        var cartItems = document.getElementsByClassName('cart-items')[0] // the div of where the cart rows are stored

            fetch('/create-checkout-session', {
                method: 'POST',
                headers: {
                    'Content-Type': 'application/json'
                },
                body:
                    JSON.stringify ({
                        items: // the items passed to the checkout screen with the quantity
                        [
                            for (var i = 0; i < cartItems.length; i++) { // a for loop so all the items in the cart will be passed through to the checkout screen

                                var cartRow = document.getElementsByClassName('cart-row')[i] // getting all the rows with the cart item

                                var itemId = cartRow.id // the id that belongs to the cart item
                                
                                {id: itemId , quantity:2}, // passing the id and quantity to the checkout screen
                            }
                        ]
                    })
                })
                .then(res => {
                    if (res.ok) return res.json()
                    return res.json().then(json => Promise.reject(json))
                })
                .then(({url}) => {
                    window.location = url
                })
                .catch(e => {
                    console.error(e)
                })
            
    }

expected that the id's of all the items in the cart would be sent with the prices on my server to the checkout screen (the checkout system is stripe)

Answer 1

You can try something like this:

 items: cartItems.map((item, index) => {id: document.getElementsByClassName('cart-row')[index], quantity: 2 })

A better way would be to include the id and quantity in the objects inside the cartItems array and so it like this:

 items: cartItems.map((item) => {id: item.id, quantity: item.quantity })