React Native Fundamentals: Cross-Platform Mobile Apps

React Native enables developers to build native mobile applications for iOS and Android using React and JavaScript. This post covers the fundamentals of React Native including core components, StyleSheet, the difference between React Native and React for the web, setting up a development environment with Expo, and why React Native is a compelling choice for cross-platform mobile development.

Why React Native?

Why should we build something in React Native? There are three main reasons why.

One is that it has a big community. Whenever you are using a technology, you want to make sure that there's enough documentation out there for you. Let's say you encounter a problem, you want to be able to Google it and find solutions that perhaps others have discovered. You want to be able to find solutions on stack overflow. You want to find libraries or tools that others have built that you can use. If you're using a brand new tool, then it's going to be really hard for you to solve those issues when nobody else in the world has had them. So react native out of Flutter or Xamarin has the biggest community. That means there are a lot of tools, a lot of components, a lot of libraries that you can use with react native to make your life easier.

Next is that big companies are using it. You want to use a technology that has been tested and has scaled, for example, some of the companies that are using React native, Facebook because they've created React native for their Facebook app manager. The Uber Eats app uses react native. So Discord, Instagram, and Skype. React Native is backed by really big companies like Shopify, Walmart but also Microsoft.

Finally, the big thing is that React native really helps us with its idea of cross-platform. Instead of a company hiring two separate teams, and maintaining two separate apps, both on IOS and Android you could write in React native ones and have it run both on IOS and Android.

Create a React Native App

To create a React Native App, we can follow a simple four-step process as we build out our UI, we are going to be writing javascript code with React Library to essentially do four things.

One is we usually import the tools that we need, so we import react and then import whatever react native components or APIs that we need.

import React from 'react';
import {Text, View} from 'react-native';

We then create our own components.

const YourApp = () => {
return (
<View
style={{
 flex: 1,
 justifyContent: 'center',
 alignItems: 'center',
 }}>
<Text>Try editing me! 🎉</Text>
</View>
);
};

And then we usually can do some fun things like creating styles for our components.

const styles = StyleSheet.create({
container: {
marginTop: 50,
},
bigBlue: {
color: 'blue',
fontWeight: 'bold',
fontSize: 30,
},
red: {
color: 'red',
},
});

And then finally we export component so we can use it in other parts of the app.

export default YourApp;

Frequently Asked Questions

What is React Native?

React Native is an open-source framework by Meta that lets you build native iOS and Android mobile applications using React and JavaScript, compiling to real native components rather than rendering in a web view.

Should you use React Native or Flutter for mobile development?

React Native is ideal if your team has strong JavaScript/React experience and you need to share code with a web app; Flutter offers better performance and a more consistent UI across platforms but requires learning Dart — both are excellent choices for cross-platform mobile development.