Align Items

import React from "react";
import { StyleSheet, View } from "react-native";
export default class Layout extends React.Component {
    render() {
        return (
            <View style={styles.wrapper}>
                <View style={styles.container}>
                    <View style={[styles.box, styles.box1]} />
                    <View style={[styles.box, styles.box2]} />
                    <View style={[styles.box, styles.box3]} />
                </View>
                <View style={styles.container2}>
                    <View style={[styles.box, styles.box1]} />
                    <View style={[styles.box, styles.box2]} />
                    <View style={[styles.box, styles.box3]} />
                </View>
            </View>
        );
    }
}

const styles = StyleSheet.create({
    wrapper: {
        flex: 1
    },
    container: {
        flex: 0.5,
        flexDirection: "row",
        justifyContent: "flex-start",
        borderBottomWidth: 2,
        borderBottomColor: "#000"
    },
    container2: {
        flex: 0.5,
        flexDirection: "row",
        alignItems: 'flex-start'
    },
    box: {
        height: 100,
        width: 100
    },
    box1: {
        backgroundColor: "#2196F3"
    },
    box2: {
        backgroundColor: "#8BC34A"
    },
    box3: {
        backgroundColor: "#e3aa1a"
    }
});