Page.tsx as route definition in NextJS

Introduction

In Next.js, a file named page.tsx inside a folder automatically becomes the page for that route. This makes it easy to create pages by just adding files.

You want to create a new page on your website by adding a folder with a <code>page.tsx</code> file.

You want to organize routes clearly by grouping related files in folders.

You want to use TypeScript for your page components with automatic routing.

You want to follow Next.js 13+ App Router conventions for defining routes.

Syntax

NextJS

export default function Page() {
  return (
    <main>
      <h1>Hello from this route!</h1>
    </main>
  )
}

The file must be named page.tsx exactly to define a route.

The default exported function is the React component shown for that route.

Examples

This defines the home page if placed in the app folder directly.

NextJS

export default function Page() {
  return <h1>Home Page</h1>
}

Placed inside app/about/page.tsx, this becomes the /about page.

NextJS

export default function Page() {
  return <p>About us content here.</p>
}

Placed inside app/contact/page.tsx, this defines the /contact route.

NextJS

export default function Page() {
  return <div>Contact page with form</div>
}

Sample Program

This is a simple page component that will show a heading and paragraph when you visit the route where this page.tsx file is located.

NextJS

export default function Page() {
  return (
    <main>
      <h1>Welcome to My Site</h1>
      <p>This is the home page defined by page.tsx</p>
    </main>
  )
}

Important Notes

Each folder inside the app directory with a page.tsx file becomes a route.

You can nest folders to create nested routes easily.

Use semantic HTML tags like <main> and <h1> for better accessibility.

Summary

page.tsx files define routes automatically in Next.js App Router.

Place a page.tsx file inside a folder to create that route.

The default export is the React component shown on that route.

Practice

1. In Next.js App Router, what does a Page.tsx file represent?

easy

A. A route that renders the default exported React component

B. A configuration file for server settings

C. A CSS stylesheet for styling components

D. A utility file for API calls

Solution

1. Step 1: Understand the role of Page.tsx in Next.js App Router

   A Page.tsx file automatically defines a route based on its folder location.

2. Step 2: Identify what the file exports

   The default export of Page.tsx is the React component rendered when visiting that route.

3. Final Answer:

   A route that renders the default exported React component -> Option A

4. Quick Check:

   Page.tsx = route component [OK]

Hint: Page.tsx file = route + component [OK]

Common Mistakes:

• Thinking Page.tsx is for styling or config
• Confusing Page.tsx with API route files
• Assuming Page.tsx exports multiple components

2. Which of the following is the correct way to define a route component in Page.tsx?

easy

A. export default function Page() { return Hello }

B. function Page() { return Hello }

C. export function Page() { return Hello }

D. const Page = () => { Hello }

Solution

1. Step 1: Check for default export

   Next.js requires the route component to be the default export from Page.tsx.

2. Step 2: Verify the function returns JSX correctly

   The function must return JSX explicitly; arrow functions need a return statement or parentheses.

3. Final Answer:

   export default function Page() { return <div>Hello</div> } -> Option A

4. Quick Check:

   Default export + returns JSX = export default function Page() { return
   Hello } [OK]

Hint: Default export function returning JSX is correct [OK]

Common Mistakes:

• Missing default export
• Arrow function without return statement
• Named export instead of default

3. Given this folder structure in Next.js App Router:
/app/about/Page.tsx exports a component showing <h1>About Us</h1>.
What will be rendered when visiting /about in the browser?

medium

A. An error because Page.tsx is missing

B. About Us

C. A blank page

D. The content of the root Page.tsx

Solution

1. Step 1: Map folder to route

   The folder /app/about corresponds to the route /about.

2. Step 2: Render the default export from Page.tsx

   The Page.tsx inside /about exports a component rendering <h1>About Us</h1>.

3. Final Answer:

   <h1>About Us</h1> -> Option B

4. Quick Check:

   Folder name = route, Page.tsx renders component [OK]

Hint: Folder name = route URL, Page.tsx renders content [OK]

Common Mistakes:

• Confusing root Page.tsx with nested routes
• Expecting error if Page.tsx exists
• Thinking route needs explicit config

4. What is wrong with this Page.tsx file?

export default function Page() {
  
Welcome

}

medium

A. Function name must be lowercase

B. Page.tsx cannot export a function

C. JSX must be wrapped in a fragment

D. Missing return statement inside the function

Solution

1. Step 1: Check function body for return

   The function body has JSX but no return keyword, so it returns undefined.

2. Step 2: Understand JSX rendering requirement

   React components must return JSX explicitly or implicitly; missing return causes no render.

3. Final Answer:

   Missing return statement inside the function -> Option D

4. Quick Check:

   JSX without return = error [OK]

Hint: Always return JSX from component functions [OK]

Common Mistakes:

• Assuming JSX auto-returns without return
• Thinking function name case matters
• Believing JSX must be wrapped in fragment always

5. You want to create a nested route /dashboard/settings in Next.js App Router. Which folder and file structure correctly defines this route?

hard

A. /app/dashboard-settings/Page.tsx

B. /app/dashboard/Page.tsx and /app/settings/Page.tsx

C. /app/dashboard/settings/Page.tsx with default export component

D. /app/dashboard/settings.tsx

Solution

1. Step 1: Understand nested route folder structure

   Nested routes are created by nesting folders inside /app matching the URL path segments.

2. Step 2: Identify correct file placement

   The route /dashboard/settings requires /app/dashboard/settings/Page.tsx with a default export component.

3. Final Answer:

   /app/dashboard/settings/Page.tsx with default export component -> Option C

4. Quick Check:

   Nested folders + Page.tsx = nested route [OK]

Hint: Nested folders match nested routes, Page.tsx inside last folder [OK]

Common Mistakes:

• Placing Page.tsx in wrong folder
• Using dash instead of nested folders
• Naming file settings.tsx instead of Page.tsx