import React, { useEffect } from "react";import { Text, View, StyleSheet, BackHandler, Alert } from "react-native";const App = () => {
  useEffect(() => {
    const backAction = () => {
      Alert.alert("Hold on!", "Are you sure you want to go back?", [
        {text: "Cancel",
          onPress: () => null,
          style: "cancel"},
        { text: "YES", onPress: () => BackHandler.exitApp() }
      ]);
      return true;
    };
    const backHandler = BackHandler.addEventListener(
      "hardwareBackPress",
      backAction
    );
    return () => backHandler.remove();
  }, []);
  return (
    <View style={styles.container}>
      <Text style={styles.text}>Click Back button!</Text>
    </View>
  );};const styles = StyleSheet.create({
  container: { flex: 1, alignItems: "center", justifyContent: "center"},
  text: { fontSize: 18, fontWeight: "bold"}});export default App;