Why routing is needed for SPAs in Angular - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the Angular routing module.

Angular

import { [1] } from '@angular/router';

Drag options to blanks, or click blank then click option'

AFormsModule

BRouterModule

CHttpClientModule

DCommonModule

Attempts:

3 left

💡 Hint

Common Mistakes

Importing unrelated modules like HttpClientModule instead of RouterModule.

The RouterModule is the Angular module that enables routing in Single Page Applications.

2fill in blank

medium

Complete the code to define a route path for the HomeComponent.

Angular

const routes = [{ path: '', component: [1] }];

Drag options to blanks, or click blank then click option'

AHomeComponent

BLoginComponent

CDashboardComponent

DProfileComponent

Attempts:

3 left

💡 Hint

Common Mistakes

Using a component unrelated to the home page for the default path.

The empty path ('') usually points to the HomeComponent as the default page in SPAs.

3fill in blank

hard

Fix the error in the routing import to enable routing in the app module.

Angular

@NgModule({ imports: [[1].forRoot(routes)] })

Drag options to blanks, or click blank then click option'

ARouterModule

BHttpClientModule

CFormsModule

DBrowserModule

Attempts:

3 left

💡 Hint

Common Mistakes

Using modules that do not have the forRoot method like HttpClientModule.

The RouterModule.forRoot(routes) method sets up the router with the route definitions.

4fill in blank

hard

Fill both blanks to create a link that navigates to the About page.

Angular

<a [1]="/about">About</a>
<[2]></[2]>

Drag options to blanks, or click blank then click option'

ArouterLink

Bhref

Crouter-outlet

DngIf

Attempts:

3 left

💡 Hint

Common Mistakes

Using href instead of routerLink for navigation in Angular.

The routerLink directive creates navigation links, and router-outlet is the placeholder where routed components display.

5fill in blank

hard

Fill all three blanks to define routes for Home, About, and Contact components.

Angular

const routes = [
  { path: '', component: [1] },
  { path: 'about', component: [2] },
  { path: 'contact', component: [3] }
];

Drag options to blanks, or click blank then click option'

AHomeComponent

BAboutComponent

CContactComponent

DLoginComponent

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up component names or using unrelated components.

Each route path should map to its respective component: Home, About, and Contact.

Practice

1. Why do Single Page Applications (SPAs) like Angular apps need routing?

easy

A. To disable navigation between different parts of the app

B. To change views without reloading the whole page

C. To make the app slower by adding extra steps

D. To reload the entire website every time a link is clicked

Solution

1. Step 1: Understand SPA behavior

   SPAs load a single HTML page and dynamically update content without full reloads.

2. Step 2: Role of routing in SPAs

   Routing allows changing views or components based on URL without reloading the entire page, making navigation smooth.

3. Final Answer:

   To change views without reloading the whole page -> Option B

4. Quick Check:

   Routing enables smooth view changes = D [OK]

Hint: Routing lets SPAs switch views without full page reloads [OK]

Common Mistakes:

• Thinking SPAs reload the whole page on navigation
• Believing routing slows down the app
• Confusing routing with disabling navigation

2. Which of the following is the correct way to define a route in Angular?

easy

A. { link: 'home', page: HomeComponent }

B. { url: 'home', view: HomeComponent }

C. { route: 'home', element: HomeComponent }

D. { path: 'home', component: HomeComponent }

Solution

1. Step 1: Recall Angular route syntax

   Angular routes use objects with path and component keys.

2. Step 2: Match correct keys

   Only { path: 'home', component: HomeComponent } uses path and component correctly.

3. Final Answer:

   { path: 'home', component: HomeComponent } -> Option D

4. Quick Check:

   Angular routes use path and component keys = A [OK]

Hint: Angular routes use 'path' and 'component' keys [OK]

Common Mistakes:

• Using wrong keys like url or route instead of path
• Confusing component with element or view
• Mixing route object structure with HTML attributes

3. Given this Angular route configuration:

const routes = [
  { path: '', component: HomeComponent },
  { path: 'about', component: AboutComponent }
];

What component will display when the URL is /about?

medium

A. HomeComponent

B. No component, shows blank page

C. AboutComponent

D. Error page component

Solution

1. Step 1: Match URL to route path

   The URL /about matches the route with path: 'about'.

2. Step 2: Identify component for matched route

   The route with path: 'about' uses AboutComponent.

3. Final Answer:

   AboutComponent -> Option C

4. Quick Check:

   URL '/about' loads AboutComponent = C [OK]

Hint: URL path matches route path to load component [OK]

Common Mistakes:

• Assuming empty path matches '/about'
• Thinking HomeComponent loads for all URLs
• Expecting error or blank page without reason

4. What is wrong with this Angular routing code?

const routes = [
  { path: 'home', component: HomeComponent },
  { path: 'about', component: AboutComponent }
];

@NgModule({
  imports: [RouterModule.forRoot(routes)],
  exports: [RouterModule]
})
export class AppRoutingModule {}

The app does not navigate to the About page when clicking the link <a routerLink='/about'>About</a>.

medium

A. RouterModule is not imported in the main app module

B. The routes array is missing a default route for '' path

C. routerLink should be written as routerlink (lowercase L)

D. The component names are incorrect

Solution

1. Step 1: Check routing module setup

   The routing module is defined correctly but must be imported in the main app module to work.

2. Step 2: Identify missing import

   If AppRoutingModule is not imported in AppModule, routing won't activate, causing navigation failure.

3. Final Answer:

   RouterModule is not imported in the main app module -> Option A

4. Quick Check:

   Routing module must be imported in app module = B [OK]

Hint: Always import routing module in main app module [OK]

Common Mistakes:

• Thinking routerLink attribute is case-sensitive
• Assuming default route is required for all navigation
• Blaming component names without error evidence

5. You want your Angular SPA to show a 'Not Found' page when users enter an unknown URL. How should you add this behavior using routing?

hard

A. Add a route with path: '**' and a NotFoundComponent

B. Add a route with path: '' and a NotFoundComponent

C. Add a route with path: '404' and redirect all unknown URLs manually

D. No routing needed; Angular shows a default error page automatically

Solution

1. Step 1: Understand wildcard route usage

   Angular uses path: '**' as a wildcard to catch all unmatched URLs.

2. Step 2: Assign NotFoundComponent to wildcard route

   Defining { path: '**', component: NotFoundComponent } shows the Not Found page for unknown URLs.

3. Final Answer:

   Add a route with path: '**' and a NotFoundComponent -> Option A

4. Quick Check:

   Wildcard '**' route handles unknown URLs = A [OK]

Hint: Use '**' path to catch unknown URLs for Not Found page [OK]

Common Mistakes:

• Using empty path '' for Not Found page
• Manually redirecting unknown URLs instead of wildcard
• Expecting Angular to handle unknown URLs without setup