App.js

/**
 * Sample React Native App
 * https://github.com/facebook/react-native
 *
 * @format
 * @flow
 */

import React, {Component} from 'react';
import {Platform, StyleSheet, Text, View, Alert, Button} from 'react-native';

const instructions = Platform.select({
  ios: 'Press Cmd+R to reload,\n' + 'Cmd+D or shake for dev menu',
  android:
    'Double tap R on your keyboard to reload,\n' +
    'Shake or press menu button for dev menu',
});

type Props = {};
export default class App extends Component<Props> {

  alertButton = () => {
    Alert.alert(
      'This is first alert message',
      'My alert Message 1',
      [
        {text: 'Ask me later', onPress: () => console.log('Ask me later pressed')},
        {
          text: 'Cancel',
          onPress: () => console.log('Cancel Pressed'),
          style: 'cancel',
        },
        {text: 'OK', onPress: () => console.log('OK Pressed')},
      ],
    );
  }

  alertButton2 = () => {
    Alert.alert(
      'This is SECOND alert message',
      'My alert Message 2',
      [
        {text: 'Ask me later', onPress: () => console.log('Ask me later pressed')},
        {
          text: 'Cancel',
          onPress: () => console.log('Cancel Pressed'),
          style: 'cancel',
        },
        {text: 'OK', onPress: () => console.log('OK Pressed')},
      ],
    );
  }

  render() {
    return (
      <View 
        accessible={true}
        accessibilityLabel="testview1"
        style={styles.container}>
        <Text 
        accessible={true}
        accessibilityLabel="testtext1"
        style={styles.welcome}>Welcome to React Native! 4</Text>
        <Text style={styles.instructions}>To get started, edit App.js</Text>
        <Text style={styles.instructions}>{instructions}</Text>
        <Button
        accessible
        accessibilityLabel="test-button-1"
        onPress={() => this.alertButton()}
        title="Click me"></Button>
         <Button
        accessible
        accessibilityLabel="test-button-2"
        onPress={() => this.alertButton2()}
        title="Click me too: SECOND"></Button>
      </View>
    );
  }
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
    backgroundColor: '#F5FCFF',
  },
  welcome: {
    fontSize: 20,
    textAlign: 'center',
    margin: 10,
  },
  instructions: {
    textAlign: 'center',
    color: '#333333',
    marginBottom: 5,
  },
});