Project structure overview in React Native

Introduction

Knowing the project structure helps you find files easily and understand how your app is organized.

When you start a new React Native app and want to know where to put your code.

When you want to add images or styles to your app and need to find the right folder.

When you want to fix bugs or add features and need to understand how files connect.

When you share your project with others and want them to understand it quickly.

Syntax

React Native

myApp/
  ├─ android/
  ├─ ios/
  ├─ src/
  │   ├─ components/
  │   ├─ screens/
  │   ├─ assets/
  │   ├─ App.js
  ├─ package.json
  ├─ babel.config.js
  └─ node_modules/

android/ and ios/ folders contain platform-specific code.

src/ is where your app's main code lives, like components and screens.

Examples

Example files inside the src folder: a button component, a home screen, and an image.

React Native

src/components/Button.js
src/screens/HomeScreen.js
src/assets/logo.png

Important config files and dependencies folder at the project root.

React Native

package.json
babel.config.js
node_modules/

Sample App

This is a simple React Native app component placed inside src/App.js. It shows a welcome message centered on the screen.

React Native

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

export default function App() {
  return (
    <View style={styles.container}>
      <Text style={styles.title}>Welcome to MyApp</Text>
    </View>
  );
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
    backgroundColor: '#f0f0f0'
  },
  title: {
    fontSize: 24,
    fontWeight: 'bold'
  }
});

Important Notes

Keep your code organized by grouping similar files in folders like components and screens.

Platform folders android and ios are usually not changed often unless you add native code.

Use package.json to manage your app's dependencies and scripts.

Summary

React Native projects have folders for platform code and app code.

Organize your app code inside src for clarity.

Understanding structure helps you build and maintain your app easily.

Practice

1. In a typical React Native project, where should you place your main app code for better organization?

easy

A. Inside the android folder

B. Directly in the root folder

C. Inside a folder named src

D. Inside the ios folder

Solution

1. Step 1: Understand folder roles

   The android and ios folders contain platform-specific native code, not app logic.

2. Step 2: Identify app code location

   App code is best organized inside a src folder to keep it separate and clear.

3. Final Answer:

   Inside a folder named src -> Option C

4. Quick Check:

   App code = src folder [OK]

Hint: App code goes in src folder, not platform folders [OK]

Common Mistakes:

• Putting app code inside android or ios folders
• Keeping all code in the root folder without organization

2. Which of the following is the correct folder name for platform-specific Android code in a React Native project?

easy

A. android

B. android_src

C. AndroidCode

D. androidApp

Solution

1. Step 1: Recall standard folder names

   React Native uses android as the folder name for Android platform code by default.

2. Step 2: Compare options

   Only android matches the exact folder name used by React Native.

3. Final Answer:

   android -> Option A

4. Quick Check:

   Android folder = android [OK]

Hint: Platform folders are named exactly android and ios [OK]

Common Mistakes:

• Using camelCase or underscores in platform folder names
• Confusing app code folder with platform folders

3. Given this React Native project structure:

myApp/
├── android/
├── ios/
├── src/
│   └── App.js
└── package.json

Where will the main app component be located?

medium

A. Directly in the root folder

B. Inside ios folder

C. Inside android folder

D. Inside src folder

Solution

1. Step 1: Analyze folder contents

   The src folder contains App.js, which is the main app component file.

2. Step 2: Understand platform folders

   The android and ios folders hold native code, not React Native components.

3. Final Answer:

   Inside src folder -> Option D

4. Quick Check:

   Main app component = src/App.js [OK]

Hint: Main app code lives in src, not platform folders [OK]

Common Mistakes:

• Assuming main app code is inside android or ios
• Looking for app code in the root folder

4. You see this error when running your React Native app: "Cannot find module './App'". Your project structure is:

myApp/
├── android/
├── ios/
├── app/
│   └── App.js
└── package.json

What is the likely cause?

medium

A. The package.json file is corrupted

B. The app code is inside app folder but should be in src

C. The android folder is missing App.js

D. The ios folder is empty

Solution

1. Step 1: Identify folder mismatch

   The app code is in app folder, but React Native expects it in src or root by default.

2. Step 2: Understand module resolution

   Since the code is not where expected, the bundler cannot find ./App module.

3. Final Answer:

   App code is inside app folder but should be in src -> Option B

4. Quick Check:

   App folder mismatch = module not found error [OK]

Hint: App code folder must match import paths exactly [OK]

Common Mistakes:

• Ignoring folder naming conventions
• Assuming platform folders hold app code
• Not checking import paths

5. You want to add a new feature to your React Native app. Which project structure change helps keep your code organized and maintainable?

hard

A. Create a new folder inside src for the feature components

B. Add all new files directly to the root folder

C. Put new feature files inside the android folder

D. Mix new feature files with existing files in ios folder

Solution

1. Step 1: Understand best practices for organization

   Keeping feature code inside src in dedicated folders helps maintain clarity and separation.

2. Step 2: Avoid mixing platform and app code

   Platform folders android and ios are for native code, not React Native components.

3. Final Answer:

   Create a new folder inside src for the feature components -> Option A

4. Quick Check:

   Organize features inside src for maintainability [OK]

Hint: Keep features inside src in separate folders [OK]

Common Mistakes:

• Adding app code to platform folders
• Cluttering root folder with many files
• Not grouping related files