I am learning typescript
with React-Native
and I want to use AsyncStorage
library. When setting my state after reading value from the storage, I got this problem:
const value: string | null Argument of type 'string | null' is notassignable to parameter of type 'SetStateAction<never[]>'. Type'null' is not assignable to type 'SetStateAction<never[]>'
The App is showing the value but I want to learn how to solve the problem. I guess I have to assign a type
to the useState
, but do not know how to assign SetStateAction
type.
How do I set the type to the useState
to solve this problem?
This is the sample code:
import React, {useEffect, useState} from 'react';import {Text, View} from 'react-native';import AsyncStorage from '@react-native-async-storage/async-storage';const App = () => { const [value, setValue] = useState([]); async function saveValue(key: string, value: string) { await AsyncStorage.setItem(key, value); } async function readValue(key: string) { const value = await AsyncStorage.getItem(key); setValue(value); } useEffect(() => { saveValue('123', 'Hello world! '); readValue('123'); }, []); return (<View><Text>{value}</Text></View> );};export default App;
Thank you.