Answers for "save object in state hook react"

prevstate in usestate

const [prevState, setState] = React.useState([]);

setState(prevState => [...prevState, 'somedata'] );

update state in useState hook

// declare state using useState hook.
// someState is set to someInitialState
const [someState, setSomeState] = useState(someInitialState);

// setSomeState updates the current state 
setSomeState(someOtherState);