Defining routes array in Angular - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a basic routes array with a path and component.

Angular

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

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

AHomeComponent

BRouterModule

CNgModule

DAppComponent

Attempts:

3 left

💡 Hint

Common Mistakes

Using RouterModule instead of a component.

Using NgModule which is for module definition.

Using AppComponent when the route is for home.

The routes array requires a component to display for the given path. Here, HomeComponent is the correct component to use.

2fill in blank

medium

Complete the code to import the Routes type from Angular router.

Angular

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

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

ARoutes

BNgModule

CRouterModule

DComponent

Attempts:

3 left

💡 Hint

Common Mistakes

Importing RouterModule instead of Routes.

Importing NgModule which is unrelated here.

Importing Component which is for components.

The Routes type is imported from '@angular/router' to define the routes array.

3fill in blank

hard

Fix the error in the routes array by completing the path property correctly.

Angular

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

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

Aabout

B`about`

C"about"

D'about'

Attempts:

3 left

💡 Hint

Common Mistakes

Leaving the path without quotes causes syntax errors.

Using backticks without template expressions is unnecessary.

The path value must be a string literal in quotes. Using single quotes like 'about' is correct.

4fill in blank

hard

Fill both blanks to define a route with an empty path and redirect to 'home'.

Angular

const routes: Routes = [ { path: [1], redirectTo: [2], pathMatch: 'full' } ];

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

A''

B'home'

C'about'

D'main'

Attempts:

3 left

💡 Hint

Common Mistakes

Using non-empty strings for the default path.

Redirecting to a path that does not exist.

An empty string '' is used for the default path, and 'home' is the redirect target.

5fill in blank

hard

Fill all three blanks to define a route with path 'profile', component ProfileComponent, and a data property with title 'User Profile'.

Angular

const routes: Routes = [ { path: [1], component: [2], data: { title: [3] } } ];

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

A'profile'

BProfileComponent

C'User Profile'

D'dashboard'

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting quotes around strings.

Putting quotes around component names.

The path is 'profile', the component is ProfileComponent, and the data title is 'User Profile'.

Practice

1. What does the routes array in Angular define?

easy

A. It defines the styles for each component.

B. It lists all services used in the app.

C. It tells Angular which component to show for each URL path.

D. It sets the database connection strings.

Solution

1. Step 1: Understand the purpose of routes array

   The routes array maps URL paths to components so Angular knows what to display.

2. Step 2: Eliminate unrelated options

   Styles, services, and database connections are not handled by routes.

3. Final Answer:

   It tells Angular which component to show for each URL path. -> Option C

4. Quick Check:

   Routes array = component mapping [OK]

Hint: Routes array links URL paths to components [OK]

Common Mistakes:

• Confusing routes with styles or services
• Thinking routes handle backend connections
• Assuming routes define component logic

2. Which of the following is the correct way to define a route for path 'home' with component HomeComponent?

easy

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

B. { path: 'home', redirectTo: HomeComponent }

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

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

Solution

1. Step 1: Check correct property names

   The route object must have path and component properties.

2. Step 2: Verify component value type

   The component value should be the component class, not a string or redirect.

3. Final Answer:

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

4. Quick Check:

   Use path and component keys correctly [OK]

Hint: Use component class, not string or redirectTo for components [OK]

Common Mistakes:

• Using 'route' instead of 'path'
• Setting component as a string
• Using redirectTo instead of component for components

3. Given this routes array:

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

What component will Angular show when the URL path is '/contact'?

medium

A. HomeComponent

B. AboutComponent

C. No component, error occurs

D. NotFoundComponent

Solution

1. Step 1: Match URL path to routes

   Path '/contact' does not match '' or 'about'.

2. Step 2: Use wildcard '**' route

   The '**' path catches all unmatched URLs and shows NotFoundComponent.

3. Final Answer:

   NotFoundComponent -> Option D

4. Quick Check:

   Wildcard '**' = NotFoundComponent [OK]

Hint: Unmatched paths go to '**' route component [OK]

Common Mistakes:

• Assuming empty path matches all URLs
• Thinking unmatched paths cause errors
• Confusing wildcard '**' with empty path

4. Identify the error in this routes array:

const routes = [
  { path: '', component: HomeComponent },
  { path: 'profile', redirectTo: 'user' },
  { path: 'user', component: UserComponent }
];

What is wrong with the route for 'profile'?

medium

A. redirectTo should be used with pathMatch property.

B. redirectTo cannot be used in routes array.

C. component is missing for 'profile' route.

D. Path 'user' should be capitalized.

Solution

1. Step 1: Check redirectTo usage

   When using redirectTo, Angular requires a pathMatch property to specify matching strategy.

2. Step 2: Confirm missing pathMatch causes error

   Without pathMatch, Angular cannot decide when to redirect, causing routing errors.

3. Final Answer:

   redirectTo should be used with pathMatch property. -> Option A

4. Quick Check:

   redirectTo needs pathMatch [OK]

Hint: Always add pathMatch with redirectTo routes [OK]

Common Mistakes:

• Omitting pathMatch with redirectTo
• Thinking redirectTo needs component
• Assuming path names must be capitalized

5. You want to define routes so that:
- The home page shows HomeComponent at path ''.
- The about page shows AboutComponent at path 'about'.
- Any unknown path redirects to home.

Which routes array correctly implements this?

hard

A. [
{ path: '', component: HomeComponent },
{ path: 'about', component: AboutComponent },
{ path: '**', redirectTo: '' }
]

B. [
{ path: '', component: HomeComponent },
{ path: 'about', component: AboutComponent },
{ path: '**', redirectTo: '', pathMatch: 'full' }
]

C. [
{ path: '', component: HomeComponent },
{ path: 'about', component: AboutComponent },
{ path: '*', redirectTo: '', pathMatch: 'full' }
]

D. [
{ path: '', component: HomeComponent },
{ path: 'about', component: AboutComponent },
{ path: '**', component: HomeComponent }
]

Solution

1. Step 1: Check wildcard path for unknown URLs

   The wildcard path for unknown URLs is '**', not '*'.

2. Step 2: Confirm redirectTo usage with pathMatch

   Redirect routes must include pathMatch: 'full' to work properly.

3. Step 3: Verify redirect target and components

   Redirecting '**' to '' sends unknown URLs to home page correctly.

4. Final Answer:

   [ { path: '', component: HomeComponent }, { path: 'about', component: AboutComponent }, { path: '**', redirectTo: '', pathMatch: 'full' } ] -> Option B

5. Quick Check:

   Use '**' with redirectTo and pathMatch 'full' [OK]

Hint: Use '**' wildcard with redirectTo and pathMatch 'full' [OK]

Common Mistakes:

• Using '*' instead of '**' for wildcard
• Omitting pathMatch in redirectTo routes
• Using component instead of redirectTo for redirects