反应 useState 收到或默认 state

Question

I think it is good time to improve something in the code:D

Listen => Code

// props.selectedProduct.quantity = '5'
const [quantity, setQuantity] = useState(props.selectedProduct?.quantity || '1')

Even when I receive quantity = '5' the || is set the default value to '1'

Why my Brothers?

How could we improve it?

I know that we can do something like props.selectedProduct?.quantity? props.selectedProduct?.quantity: '1' props.selectedProduct?.quantity? props.selectedProduct?.quantity: '1' but is there any more smart way to achieve our target/mission to be more happy every day?

Bless you Devs

Answer 1

You are not using useState correctly and this is why you have problems with it.

You DO NOT update the state by forwarding props(.).

If you want to update a state you use the setState function.

If you are using your state in multiple childs, you should use Context or any other state managment such as recoil, redux, etc...

You should learn more about React and React Hooks here: React Docs