Usage
Async Storage can only store string
data. In order to store object data,
you need to serialize it first. For data that can be serialized to JSON, you can
use JSON.stringify()
when saving the data and JSON.parse()
when loading the
data.
Importing
import AsyncStorage from '@react-native-async-storage/async-storage';
Storing data
setItem()
is used both to add new data item (when no data for given key
exists), and to modify existing item (when previous data for given key exists).
Storing string value
const storeData = async (value) => {
try {
await AsyncStorage.setItem('my-key', value);
} catch (e) {
// saving error
}
};
Storing object value
const storeData = async (value) => {
try {
const jsonValue = JSON.stringify(value);
await AsyncStorage.setItem('my-key', jsonValue);
} catch (e) {
// saving error
}
};
Reading data
getItem
returns a promise that either resolves to stored value when data is
found for given key, or returns null
otherwise.
Reading string value
const getData = async () => {
try {
const value = await AsyncStorage.getItem('my-key');
if (value !== null) {
// value previously stored
}
} catch (e) {
// error reading value
}
};
Reading object value
const getData = async () => {
try {
const jsonValue = await AsyncStorage.getItem('my-key');
return jsonValue != null ? JSON.parse(jsonValue) : null;
} catch (e) {
// error reading value
}
};
More
For more examples, head over to API section.