Storing application data

The AsyncStorage API works the same on both the iOS and Android platforms. You would use this API for applications that don't require any network connectivity in the first place or to store data that will eventually be synchronized using an API endpoint once a network becomes available.

Let's look at some code that allows the user to enter a key and a value, and then stores them:

import React, { useState, useEffect } from "react";
import { Text, TextInput, View, FlatList, AsyncStorage } from "react-native";
import styles from "./styles";
import Button from "./Button";

export default function App() {
  const [key, setKey] = useState(null);
  const [value, setValue] = useState(null);
  const [source, setSource] = useState([]);

  function setItem() {
    return AsyncStorage.setItem(key, value)
      .then(() => {
        setKey(null);
        setValue(null);
      })
      .then(loadItems);
  }

  function clearItems() {
    return...