Create Next App setup in NextJS - Practice Problems & Coding Challenges

Challenge - 5 Problems

📝 Syntax

intermediate

Correct command to create a new Next.js app

Which command correctly creates a new Next.js app named my-app using the official recommended method?

A npx create-next-app@latest my-app

B npm create next-app my-app

C next new my-app

D npm init next-app my-app

💡 Hint

Use the official Next.js recommended command with npx.

The official way to create a new Next.js app is using 'npx create-next-app@latest my-app'. Other commands are either invalid or deprecated.

❓ component_behavior

intermediate

Default page output after creating a Next.js app

After running npx create-next-app@latest my-app and starting the development server, what will the default homepage display?

A A list of all files in the project directory

B A blank white page with no content

C A welcome page with Next.js logo and links to documentation

D An error page saying 'Page Not Found'

💡 Hint

The default app includes a friendly welcome page.

The default Next.js app shows a styled welcome page with the Next.js logo and helpful links to get started.

🔧 Debug

advanced

Fixing a missing dependency error after setup

You created a Next.js app with npx create-next-app@latest my-app but running npm run dev gives an error: Cannot find module 'react'. What is the most likely cause?

A You must rename <code>package.json</code> to <code>next.json</code>

B The Next.js app template does not include React by default

C You need to downgrade Node.js to version 12

D You forgot to run <code>npm install</code> before <code>npm run dev</code>

💡 Hint

Dependencies must be installed before running the app.

The error means React is missing. Running npm install installs all dependencies including React.

🧠 Conceptual

advanced

Understanding the role of the pages directory

In a freshly created Next.js app, what is the main purpose of the pages directory?

A It stores global CSS styles for the entire app

B It automatically maps files to routes for the app's URLs

C It contains configuration files for the Next.js build process

D It holds server-side API code only

💡 Hint

Think about how URLs relate to files in Next.js.

Next.js uses the pages folder to create routes automatically based on file names.

❓ state_output

expert

Effect of editing app/page.tsx in Next.js 14 app router

In a Next.js 14 app created with the app router, you edit app/page.tsx to add a console.log('Hello') inside the default exported component function. What happens when you refresh the homepage in the browser?

NextJS

export default function Page() {
  console.log('Hello');
  return <h1>Welcome</h1>;
}

A The message 'Hello' appears in the server console, not the browser console

B The message 'Hello' appears in the browser console each time the page loads

C No console message appears anywhere because console.log is ignored

D The app crashes with a runtime error due to console.log usage

💡 Hint

Remember that Next.js 14 app router components run on the server by default.

In Next.js 14 app router, components are server components by default, so console.log runs on the server, not in the browser.

Practice

1. What does the command npx create-next-app@latest do when setting up a Next.js project?

easy

A. It creates a new Next.js project with default settings and dependencies installed.

B. It updates an existing Next.js project to the latest version.

C. It runs the Next.js development server immediately.

D. It installs only React without Next.js features.

Solution

1. Step 1: Understand the purpose of npx create-next-app@latest

   This command scaffolds a new Next.js project with all necessary files and dependencies.

2. Step 2: Differentiate from other commands

   It does not update or run servers; it only creates a fresh project setup.

3. Final Answer:

   It creates a new Next.js project with default settings and dependencies installed. -> Option A

4. Quick Check:

   Project creation = A [OK]

Hint: Remember: create-next-app sets up a new project [OK]

Common Mistakes:

• Confusing create-next-app with update commands
• Thinking it runs the server automatically
• Assuming it installs only React

2. Which of the following is the correct command to start the Next.js development server after creating the app?

easy

A. npm start

B. npm run dev

C. next dev

D. node server.js

Solution

1. Step 1: Identify the standard Next.js development command

   After setup, npm run dev starts the development server with hot reload.

2. Step 2: Compare with other commands

   npm start is usually for production, next dev is a lower-level command but not standard npm script, and node server.js is unrelated here.

3. Final Answer:

   npm run dev -> Option B

4. Quick Check:

   Dev server start = A [OK]

Hint: Use npm run dev to start Next.js dev server [OK]

Common Mistakes:

• Using npm start instead of npm run dev
• Trying to run node server.js without setup
• Confusing next dev with npm scripts

3. After running npx create-next-app@latest my-app and then cd my-app followed by npm run dev, what will you see when you open http://localhost:3000 in your browser?

medium

A. A blank white page with no content.

B. A list of files in the project directory.

C. An error message saying the server is not running.

D. A Next.js welcome page with links to documentation and examples.

Solution

1. Step 1: Understand default Next.js app behavior

   The default Next.js app shows a welcome page with helpful links after setup and running dev server.

2. Step 2: Eliminate other options

   Blank page means no content, error means server not running, and file list is not default behavior.

3. Final Answer:

   A Next.js welcome page with links to documentation and examples. -> Option D

4. Quick Check:

   Default page = B [OK]

Hint: Default Next.js app shows welcome page on localhost:3000 [OK]

Common Mistakes:

• Expecting a blank page instead of welcome content
• Assuming server is not running after npm run dev
• Thinking file list is shown by default

4. You ran npx create-next-app@latest but when you try npm run dev, you get an error: command not found: next. What is the likely cause?

medium

A. You ran npm run dev outside the project folder.

B. You need to restart your computer after installation.

C. You forgot to install Node.js on your system.

D. Your internet connection is down.

Solution

1. Step 1: Analyze the error message

   The error command not found: next usually means the Next.js binary is not found in current folder's node_modules.

2. Step 2: Check common causes

   This happens if you run npm run dev outside the project directory where dependencies are installed.

3. Final Answer:

   You ran npm run dev outside the project folder. -> Option A

4. Quick Check:

   Run commands inside project folder = C [OK]

Hint: Always run npm scripts inside your project folder [OK]

Common Mistakes:

• Assuming Node.js is not installed when it is
• Restarting computer unnecessarily
• Blaming internet connection for local command errors

5. You want to create a new Next.js app named blog but also want to use TypeScript from the start. Which command should you run?

hard

A. npx create-next-app@latest blog --use-typescript

B. npx create-next-app@latest blog -ts

C. npx create-next-app@latest blog --typescript

D. npx create-next-app@latest blog --ts

Solution

1. Step 1: Recall official flag for TypeScript setup

   The official flag to create a Next.js app with TypeScript is --typescript.

2. Step 2: Verify other options

   Short flags like -ts or --ts are not recognized, and --use-typescript is invalid.

3. Final Answer:

   npx create-next-app@latest blog --typescript -> Option C

4. Quick Check:

   Use --typescript flag = D [OK]

Hint: Use --typescript flag to create TS Next.js app [OK]

Common Mistakes:

• Using incorrect or shorthand flags
• Assuming TypeScript is default without flag
• Trying unsupported flag names