Question 53447 in Javascript Question posted in
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I want to change value of count , what's wrong in this code? ( React Function Component ) – Javascript

const [user, setUser] = useState({firstName: "AA",lastName: "BB",address: [{name: "AA",count: 0}]});
const plus = () => {setUser([ ...user.address, user.address[0].count + 1 ]);}
return (
<h1>{user.address[0].count}
)

I tried to wrap up setUser to object

Tags:

2

Answers


  1. 0

    Spread the object and inner array separately when updating the state:

    setUser({ ...user, address : [ {...user.address[0], count : user.address[0].count + 1}, 
                              ...user.address.slice(1) ] });
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  2. 0

    In your code, you are not properly updating the state. If spread operations are confusing for you, you can use immer.

    Install immer using one of the following.

    npm i immer
pnpm add immer
yarn add immer

    Then you can use immer as follows.

    import produce from "immer";

...
...

setUser(produce(state => {
  user.address[0].count += 1; 
}));

...
...
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