How to store data in AsyncStorage in react native?
When developers develop applications, they need to store information permanently for an application. The react native applications use the database to remember all the information which is related to the applications and their respective users. React Native uses AsyncStorage for data storing purpose. AsyncStorage is a simple, unencrypted synchronous, persistent, key-value storage system that is global to the application. On iOS, AsyncStorage is backed by native code that stores small values in the serialized dictionary and large values in separate files. On Android, AsyncStorage will use either RocksDB or SQLite based on which is available.
Four steps are needed to understand how to use AsyncStorage to React Native-
- Don’t need to install any extra library. By default, it comes with React Native.
Import {AsyncStorage} from 'react-native';
- AsyncStorage uses key-value pairs for saving the data for example-
AsyncStorage.setItem ('myKey', myValue);
- To load the saved data run given the command-
AsyncStorage.getItem('myKey'). then((myValue)=> {this.setState ({'myKey': myValue});});
- Since loading data is a time-consuming task, it is designed to be an asynchronous operation. So getItem returned the promise, which will invoke the call back function when the read operation is completed.
BY Best Interview Question ON 14 Nov 2019