App.js

/**
 * Sample React Native App
 * https://github.com/facebook/react-native
 *
 * @format
 * @flow
 * @lint-ignore-every XPLATJSCOPYRIGHT1
 */

import React, { Component } from "react";
import { Platform, StyleSheet, Text, View } from "react-native";

type TestProps = {
  name: string;
  age: number;
};

export class TestApp extends Component<TestProps> {
  render() {
    return (
      <View style={styles.container}>
        <Text style={styles.welcome}>{this.props.name}</Text>
        <Text style={styles.instructions}>{this.props.age}</Text>
      </View>
    );
  }
}

type Props = {
};
export default class App extends Component<Props> {
  render() {
    return (
      <View style={styles.container}>
        <Text style={styles.welcome}>Welcome to React Native!</Text>
        <Text style={styles.instructions}>To get started, edit App.js</Text>
        <TestApp name='Tinh Ngo' age={24} />
      </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
  }
});