AsyncStorage

AsyncStorage is a simple key-value storage system that allows you to persist data between multiple loads of your application. It is stored locally in the browser, so any users of the same browser will see the same data. This also means the data will not follow users from device to device – for that, you need to save objects to a server backend like Firebase.

The AsyncStorage JavaScript API is a simple facade that provides a clean Promise API around in-browser storage.

// Persisting data
try {
  await AsyncStorage.setItem('my-storage-key', 'I like to save it.');
} catch (error) {
  // Error saving data
}

// Fetching data
try {
  const value = await AsyncStorage.getItem('my-storage-key');
  if (value !== null) {
    // We have data!
    console.log(value);
  }
} catch (error) {
  // Error retrieving data
}

Methods

static getItem(key: string): Promise

Fetches an item for a key, returning a Promise that is resolved with the retrieved value, or rejected if an error occurs.

static setItem(key: string, value: string): Promise

Sets the value for a key, returning a Promise that is resolved when the save completes, or rejected if an error occurs.

static removeItem(key: string): Promise

Removes an item for a key, returning a Promise that is resolved if the remove is successful, or rejected if an error occurs.

static getAllKeys(): Promise

Gets all keys known to your app, returning a Promise that is resolved with an array of key strings.

static multiGet(keys: Array<string>): Promise

Batches the fetching of items specified in the array of key inputs. Returns a Promise that is resolved with a matching array of retrieved values, or rejected if any of the fetches fails.

static multiSet(keyValuePairs: Array<[string, string]>): Promise

Batches the storage of multiple key-value pairs. Returns a Promise that is resolved if all stores succeed, or rejected if any fail.

static multiGet(keys: Array<string>): Promise

Batches the removal of items specified in the array of key inputs. Returns a Promise that is resolved if all values are removed, or rejected if any of the deletions fails.