profile.js

import React, { Component } from 'react';
import { Platform, StyleSheet, Text, View, Button } from 'react-native';
import { createAppContainer } from 'react-navigation';
import { createStackNavigator } from 'react-navigation-stack';
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',
});
import { Tab } from './tab';
export default class Profile extends Component {
    constructor(props) {
        super(props);

    }
    render() {
        return (
            <View style={styles.container}>
                <Text style={styles.welcome}>Welcome to Hello page</Text>
                <Text style={styles.instructions}>To get started, edit App.js</Text>
                <Text style={styles.instructions}>{instructions}</Text>
                <Button
                    style={{ fontSize: 20, color: 'green' }}
                    styleDisabled={{ color: 'red' }}
                    onPress={() => this.props.navigation.navigate('Tab')}
                    title="Press Me"
                >
                    Press Me
</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,
    },
});