How to handle a complicated state in react

Background: I am kind of new to react and am learning it, I have made some sites in it but i Highly doubt my way of appraching the problem.

So while handaling a complex state .
For example lets say we have a cart which has a product which is a object and then it contains a quantity key now how can we make changes in that quantity, which will be the best way to do it ??

Example

const [cart , setcart] = useState([

{_id: "1",
    name:"product1",
    quantity: 2
},
{_id: "2",
    name:"product2",
    quantity: 1
}
]);

lets say we need to update the quantity count of the product with the
id 2 to 5. What we be the best approach, my way of doing it will be.

setcart((items)=>{
const changingItem = items.find((item)=>{return item.id === "2"});
changedItem.quantity = 5;

const newCart = items;
newCart.push(changingItem);

return newCart;
    
})

thank you

>Solution :

setCart(items => items.map(item => item.id === "2" ? {...item, quantity: 5} : item)}