Route groups with (groupName) in NextJS - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

What is the rendered output of this Next.js route group?

Consider a Next.js app router with this folder structure:

app/(admin)/dashboard/page.tsx

The (admin) folder is a route group. What URL path will render the dashboard page?

NextJS

app/(admin)/dashboard/page.tsx
export default function Dashboard() {
  return <h1>Admin Dashboard</h1>;
}

A /(admin)/dashboard

B /admin/dashboard

C /dashboard

D /dashboard/admin

💡 Hint

Route groups group routes without adding to the URL path.

Route groups in Next.js app router let you organize routes without affecting the URL. So the (admin) folder does not add 'admin' to the URL path. The dashboard page is at '/dashboard'.

📝 Syntax

intermediate

Which folder name correctly creates a route group in Next.js?

You want to create a route group named 'marketing' in your Next.js app router. Which folder name is valid?

A [marketing]

B <marketing>

C {marketing}

D (marketing)

💡 Hint

Route groups use parentheses in folder names.

Next.js route groups are created by wrapping the folder name in parentheses, like (marketing).

🔧 Debug

advanced

Why does this route group cause a 404 error?

You have this folder structure:

app/(user)/profile/page.tsx

But navigating to '/profile' shows a 404 error. What is the likely cause?

NextJS

app/(user)/profile/page.tsx
export default function Profile() {
  return <p>User Profile</p>;
}

A Route groups cannot contain pages directly

B The app folder must have a layout.tsx file for nested routes to work

C The (user) folder is missing a layout.tsx file

D The profile folder name should be in parentheses

💡 Hint

Next.js app router requires layouts to render nested pages.

In Next.js app router, the app folder needs a root layout.tsx file. Without it, nested routes like (user)/profile/page.tsx won't render and cause 404.

🧠 Conceptual

advanced

What is the main benefit of using route groups in Next.js?

Why would a developer use route groups (folders with parentheses) in a Next.js app router project?

A To organize routes without changing the URL structure

B To create dynamic route parameters

C To enable server-side rendering only for those routes

D To automatically generate API routes

💡 Hint

Think about URL paths and folder structure.

Route groups let you group files and folders for better organization without adding extra segments to the URL path.

❓ state_output

expert

What is the URL path and rendered output for nested route groups?

Given this folder structure:

app/(dashboard)/(settings)/profile/page.tsx

And the page.tsx contains:

export default function Profile() { return <h2>Profile Settings</h2>; }

What URL path shows this page and what is the rendered output?

NextJS

app/(dashboard)/(settings)/profile/page.tsx
export default function Profile() {
  return <h2>Profile Settings</h2>;
}

A URL: /profile, Output: <h2>Profile Settings</h2>

B URL: /(dashboard)/(settings)/profile, Output: <h2>Profile Settings</h2>

C URL: /profile, Output: <h1>Profile Settings</h1>

D URL: /dashboard/settings/profile, Output: <h2>Profile Settings</h2>

💡 Hint

Route groups do not add to the URL path.

Nested route groups do not add segments to the URL. So the URL is '/profile'. The page renders an h2 heading with 'Profile Settings'.

Practice

1. What is the main purpose of using route groups with (groupName) in Next.js?

easy

A. To organize routes in folders without changing the URL structure

B. To change the URL path to include the group name

C. To create dynamic routes with parameters

D. To add middleware to specific routes

Solution

1. Step 1: Understand route groups concept

   Route groups use parentheses in folder names to group routes logically without affecting the URL path.

2. Step 2: Compare URL effect

   Since the URL does not include the group name, the main purpose is organization, not URL change.

3. Final Answer:

   To organize routes in folders without changing the URL structure -> Option A

4. Quick Check:

   Route groups = organize without URL change [OK]

Hint: Parentheses folders group routes but keep URLs clean [OK]

Common Mistakes:

• Thinking group name appears in URL
• Confusing with dynamic route parameters
• Assuming it adds middleware automatically

2. Which of the following folder names correctly creates a route group named admin in Next.js?

easy

A. admin

B. (admin)

C. [admin]

D. {admin}

Solution

1. Step 1: Identify route group syntax

   Route groups use parentheses around the folder name, like (groupName).

2. Step 2: Match folder name

   The folder named (admin) correctly creates a route group called admin.

3. Final Answer:

   (admin) -> Option B

4. Quick Check:

   Parentheses folder = route group [OK]

Hint: Use parentheses for route groups, not brackets or braces [OK]

Common Mistakes:

• Using square brackets which are for dynamic routes
• Using curly braces which are invalid
• Omitting parentheses and creating normal folders

3. Given this folder structure in Next.js app router:

app/(dashboard)/page.tsx
app/(dashboard)/settings/page.tsx
app/profile/page.tsx

What URL paths will be available?

medium

A. /, /settings, /profile

B. /(dashboard), /(dashboard)/settings, /profile

C. /dashboard, /dashboard/settings, /profile

D. /dashboard, /settings, /profile

Solution

1. Step 1: Understand route groups effect on URLs

   Folders with parentheses group routes but do not add to URL path.

2. Step 2: Map folder names to URLs

   The (dashboard) group is invisible in URL, so app/(dashboard)/page.tsx maps to / because the page.tsx inside is the root of that group. Similarly, app/(dashboard)/settings/page.tsx maps to /settings. The app/profile/page.tsx maps to /profile.

3. Final Answer:

   /, /settings, /profile -> Option D

4. Quick Check:

   Route groups hide folder name but keep nested paths [OK]

Hint: Route groups hide folder name but keep nested routes [OK]

Common Mistakes:

• Including parentheses folder name in URL
• Ignoring nested folder names inside groups
• Assuming root group maps to root URL

4. You created a folder named (admin) inside app but your routes under it are not working. What is the most likely mistake?

medium

A. You forgot to add a page.tsx file inside the (admin) folder

B. You used square brackets instead of parentheses for the folder name

C. You named the folder admin without parentheses

D. You placed the (admin) folder outside the app directory

Solution

1. Step 1: Check route group folder requirements

   Route groups require a page.tsx or similar file inside to define the route component.

2. Step 2: Identify missing page file issue

   If routes inside (admin) don't work, missing page.tsx is the most common cause.

3. Final Answer:

   You forgot to add a page.tsx file inside the (admin) folder -> Option A

4. Quick Check:

   Missing page.tsx = no route rendered [OK]

Hint: Always add page.tsx inside route group folders [OK]

Common Mistakes:

• Confusing folder naming syntax
• Placing folders outside app directory
• Assuming route groups auto-create pages

5. You want to create two separate route groups (marketing) and (sales) inside app with pages home.tsx and contact.tsx each. How should you organize folders so URLs are /home and /contact without group names in URL?

hard

A. app/(marketing)/home.tsx and app/(sales)/contact/page.tsx

B. app/(marketing)/home.tsx and app/(marketing)/(sales)/contact.tsx

C. app/(marketing)/home.tsx and app/(sales)/contact.tsx

D. app/home.tsx and app/contact.tsx

Solution

1. Step 1: Use route groups to hide folder names

   Folders named with parentheses group routes without adding to URL path.

2. Step 2: Place pages inside separate route groups

   Placing home.tsx inside (marketing) and contact.tsx inside (sales) keeps URLs as /home and /contact.

3. Final Answer:

   app/(marketing)/home.tsx and app/(sales)/contact.tsx -> Option C

4. Quick Check:

   Separate groups hide folder names, URLs stay clean [OK]

Hint: Put pages inside separate parentheses folders for clean URLs [OK]

Common Mistakes:

• Nesting groups causing longer URLs
• Placing pages outside groups losing organization
• Using page.tsx inconsistently inside groups