incrementItem()
Increases the quantity of an item already in the cart by 1 (or by a custom amount).
Basic Usage
import { useShoppingCart } from 'use-shopping-cart'
function CartItem({ itemId }: { itemId: string }) {
const { incrementItem, cartDetails } = useShoppingCart()
const item = cartDetails[itemId]
return (
<div className="cart-item">
<span>{item.name}</span>
<span>Quantity: {item.quantity}</span>
<button onClick={() => incrementItem(itemId)}>+1</button>
</div>
)
}Increment by Custom Amount
You can increase the quantity by more than 1 (positive integers only):
// Increase by 10
incrementItem(itemId, { count: 10 })Complete Cart Example
function Cart() {
const { incrementItem, cartDetails, cartCount } = useShoppingCart()
if (cartCount === 0) {
return <p>Your cart is empty</p>
}
return (
<div>
{Object.entries(cartDetails).map(([id, item]) => (
<div key={id} className="cart-item">
<h4>{item.name}</h4>
<p>Quantity: {item.quantity}</p>
<button onClick={() => incrementItem(id)}>+</button>
<button onClick={() => incrementItem(id, { count: 5 })}>+5</button>
</div>
))}
</div>
)
}Interactive Demo
Cart Display
Total Items: 0
Cart is empty. Add items to see them here!
Bananas
Yummy yellow fruit
$4.00
Add to Cart First:
Add the item to your cart to try incrementing
Try incrementing items above! The cart state persists across all documentation pages.
