Project structure overview in React - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the src folder in a React project?

The src folder holds all the source code files like components, styles, and utilities that make up the React app.

beginner

Why do React projects often have a public folder?

The public folder contains static files like the main HTML file and images that do not change and are served directly to the browser.

beginner

What is the role of package.json in a React project?

package.json lists the project dependencies, scripts, and metadata. It helps manage libraries and commands for the React app.

beginner

Where do you usually put reusable UI parts in a React project?

Reusable UI parts are usually placed inside a components folder within src to keep code organized and easy to maintain.

intermediate

What is the benefit of organizing files by feature or domain in a React project?

Organizing by feature groups related files together, making the project easier to understand and scale as it grows.

Which folder usually contains the main HTML file in a React project?

A src

B components

C public

D node_modules

The public folder holds static files like the main HTML file.

Where do you put React components in a typical project structure?

A src/public

B public/components

C node_modules/components

D src/components

React components are placed inside src/components for organization.

What file lists the dependencies and scripts for a React project?

A package.json

B index.html

C README.md

D webpack.config.js

package.json manages dependencies and scripts.

Why is the src folder important?

A It contains the source code of the app

B It holds static images

C It stores build files

D It contains node modules

src is where the app's source code lives.

What is a good reason to organize files by feature in React?

A Improves browser speed

B Makes the project easier to scale and understand

C Avoids using components

D Reduces the number of files

Organizing by feature groups related code, helping with scaling and clarity.

Describe the main folders and files you find in a React project and their roles.

Think about where code lives, where static files go, and how dependencies are managed.

Explain why organizing React project files by feature or domain can help in development.

Consider how grouping things by what they do helps teamwork and growth.

Practice

1. Which folder in a React project usually contains reusable UI pieces like buttons or headers?

easy

A. pages/

B. components/

C. styles/

D. public/

Solution

1. Step 1: Understand folder purposes

   The components/ folder holds reusable UI parts like buttons or headers.

2. Step 2: Compare with other folders

   public/ holds static files, styles/ holds CSS, and pages/ holds full page components.

3. Final Answer:

   components/ -> Option B

4. Quick Check:

   Reusable UI pieces = components/ [OK]

Hint: Reusable UI parts go in components/ folder [OK]

Common Mistakes:

• Confusing public/ with components/
• Putting styles in components/
• Using pages/ for small UI parts

2. Which file is typically found inside the public/ folder in a React project?

easy

A. index.html

B. Button.jsx

C. App.js

D. styles.css

Solution

1. Step 1: Identify public folder role

   The public/ folder holds static files served directly, like index.html.

2. Step 2: Match files to folders

   App.js and Button.jsx are source code files, styles.css is usually in styles/.

3. Final Answer:

   index.html -> Option A

4. Quick Check:

   Static files like index.html = public/ [OK]

Hint: index.html is always in public/ folder [OK]

Common Mistakes:

• Putting App.js in public/
• Confusing styles.css location
• Thinking Button.jsx is static file

3. Given this React project structure inside src/:

src/
  components/
    Header.jsx
  pages/
    Home.jsx
  styles/
    main.css

Where should you import Header to use it on the home page?

medium

A. import Header from '../components/Header';

B. import Header from './components/Header';

C. import Header from '../pages/Header';

D. import Header from './Header';

Solution

1. Step 1: Locate Home.jsx and Header.jsx relative paths

   Home.jsx is inside pages/, Header.jsx is inside components/ at the same src level.

2. Step 2: Determine correct import path

   From pages/Home.jsx, since pages/ and components/ are sibling folders under src/, go up one level with '..' to src/ then into components/: '../components/Header'.

3. Step 3: Check options carefully

   import Header from './components/Header'; uses './components/Header' which assumes components inside pages/, which is incorrect. import Header from '../components/Header'; uses '../components/Header' which is correct.

4. Final Answer:

   import Header from '../components/Header'; -> Option A

5. Quick Check:

   Relative import from pages to components = ../components/Header [OK]

Hint: Use ../ to go up one folder from pages to src [OK]

Common Mistakes:

• Using ./components from pages/
• Importing from pages/ folder
• Forgetting relative path syntax

4. You see this import in a React file:
import styles from './styles.css';
But the styles folder is inside src/, at the same level as components/, and the file is inside src/components/. What is wrong?

medium

A. The import should be './styles/styles.css' instead

B. You cannot import CSS files in React

C. The import path should be '../styles/styles.css' to go up one folder

D. The styles folder should be inside components/

Solution

1. Step 1: Understand folder locations

   The file is in src/components/, styles folder is in src/. To import styles.css inside styles/, you must go up one level from components/.

2. Step 2: Fix import path

   Using './styles.css' looks for styles.css inside components/, which is wrong. The correct path is '../styles/styles.css'.

3. Step 3: Check options

   The import path should be '../styles/styles.css' to go up one folder correctly identifies the need to go up one folder into the styles folder. You cannot import CSS files in React is false (CSS can be imported). The import should be './styles/styles.css' instead looks inside components/. The styles folder should be inside components/ suggests wrong folder placement.

4. Final Answer:

   The import path should be '../styles/styles.css' to go up one folder -> Option C

5. Quick Check:

   Go up one folder to access styles folder [OK]

Hint: Use ../ to go up from components to src for styles [OK]

Common Mistakes:

• Using ./ without going up folder
• Thinking CSS can't be imported
• Wrong folder nesting assumptions

5. You want to organize a React project with these goals:
- Keep reusable UI parts separate
- Have full pages grouped
- Store CSS files in one place
- Serve static files like images and index.html

Which folder structure best fits these goals inside src/ and public/?

hard

A. src/ui/, src/screens/, src/css/, public/assets/

B. src/, public/components/, public/pages/, public/styles/

C. src/components/, src/pages/, public/styles/, public/

D. src/components/, src/pages/, src/styles/, public/

Solution

1. Step 1: Match goals to folder roles

   Reusable UI parts go in components/, full pages in pages/, CSS in styles/, static files like images and index.html in public/.

2. Step 2: Evaluate options

   src/components/, src/pages/, src/styles/, public/ matches exactly: src/components/, src/pages/, src/styles/, public/. src/ui/, src/screens/, src/css/, public/assets/ uses non-standard folder names and puts static files in public/assets/ only. src/components/, src/pages/, public/styles/, public/ puts styles in public/, which is not typical. src/, public/components/, public/pages/, public/styles/ puts components and pages in public/, which is incorrect.

3. Final Answer:

   src/components/, src/pages/, src/styles/, public/ -> Option D

4. Quick Check:

   Standard React folders = components, pages, styles, public [OK]

Hint: Use components, pages, styles in src and public for static files [OK]

Common Mistakes:

• Putting CSS in public/
• Using non-standard folder names
• Mixing src and public roles