Router outlet for view rendering in Angular - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to add a router outlet in the template.

Angular

<router-[1]></router-[1]>

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

Arender

Bview

Coutlet

Ddisplay

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'view' or 'render' instead of 'outlet'.

Forgetting the hyphen in the tag name.

The router-outlet tag is used in Angular templates to mark where routed components will be displayed.

2fill in blank

medium

Complete the code to import RouterModule with routes in an Angular module.

Angular

imports: [RouterModule.[1](routes)]

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

AforRoot

BforChild

Cconfigure

Dsetup

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'forChild' in the root module.

Using non-existent methods like 'configure' or 'setup'.

RouterModule.forRoot(routes) sets up the router at the application's root level.

3fill in blank

hard

Fix the error in the route configuration to display HomeComponent at path ''.

Angular

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

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

AHomeComponent

Bhome

ChomeComponent

DHome

Attempts:

3 left

💡 Hint

Common Mistakes

Using lowercase or partial names like 'home' or 'Home'.

Using variable names instead of component class names.

The component property must reference the component class name exactly, which is usually PascalCase and ends with 'Component'.

4fill in blank

hard

Fill both blanks to define a route for AboutComponent with path 'about'.

Angular

const routes: Routes = [{ path: '[1]', component: [2] }];

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

Aabout

BAboutComponent

Chome

DHomeComponent

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up component names or paths.

Using incorrect casing for component names.

The path string should match the URL segment, and the component should be the class to render.

5fill in blank

hard

Fill all three blanks to create a router link to 'contact' page with text 'Contact Us'.

Angular

<a routerLink="[1]">[2]</a> <!-- uses [3] directive -->

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

Acontact

BContact Us

CrouterLink

DrouterOutlet

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'routerOutlet' instead of 'routerLink' in the anchor tag.

Incorrect path or link text.

The routerLink directive sets the link path, and the anchor text is what the user sees.

Practice

1. What is the main purpose of the <router-outlet> element in an Angular application?

easy

A. It stores data for the application state.

B. It styles the navigation bar of the application.

C. It handles user input events like clicks and key presses.

D. It acts as a placeholder where Angular displays components based on the current URL.

Solution

1. Step 1: Understand the role of <router-outlet>

   This element is a special tag in Angular templates that marks where routed components will appear.

2. Step 2: Connect URL to component display

   Angular uses the router to match the URL and then loads the matching component inside the <router-outlet>.

3. Final Answer:

   It acts as a placeholder where Angular displays components based on the current URL. -> Option D

4. Quick Check:

   Router outlet = placeholder for routed views [OK]

Hint: Remember router-outlet shows views for URLs [OK]

Common Mistakes:

• Thinking router-outlet styles or handles events
• Confusing router-outlet with data storage
• Assuming router-outlet is a component itself

2. Which of the following is the correct way to include a router outlet in an Angular component template?

easy

A. <router-outlet></router-outlet>

B. <routerOutlet />

C. <router-outlet />

D. <router-outlet>

Solution

1. Step 1: Recall Angular syntax for router outlet

   The <router-outlet> is a tag that must be opened and closed properly in HTML.

2. Step 2: Check self-closing tag usage

   Angular requires <router-outlet> to have both opening and closing tags; self-closing is invalid here.

3. Final Answer:

   <router-outlet></router-outlet> -> Option A

4. Quick Check:

   Use full opening and closing tags for router-outlet [OK]

Hint: Use full tags, not self-closing for router-outlet [OK]

Common Mistakes:

• Using self-closing <router-outlet />
• Writing camelCase like <routerOutlet>
• Omitting the closing tag

3. Given the following Angular route configuration and template, what will be displayed when the URL is '/home'?

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

Template:
<router-outlet></router-outlet>

medium

A. Nothing will be displayed because the router outlet is empty.

B. The AboutComponent content will be rendered inside the router outlet.

C. The HomeComponent content will be rendered inside the router outlet.

D. An error will occur because the route is not defined.

Solution

1. Step 1: Match URL to route

   The URL '/home' matches the route with path 'home' which loads HomeComponent.

2. Step 2: Render component in router outlet

   The <router-outlet> displays the matched component's template, so HomeComponent content appears.

3. Final Answer:

   The HomeComponent content will be rendered inside the router outlet. -> Option C

4. Quick Check:

   URL '/home' loads HomeComponent in router outlet [OK]

Hint: URL matches route path to show component in router-outlet [OK]

Common Mistakes:

• Confusing which component matches the URL
• Thinking router outlet shows all components at once
• Assuming empty display means error

4. You have this Angular template:

<router-outlet></router-outlet>
<router-outlet></router-outlet>

What problem will this cause when navigating routes?

medium

A. Both router outlets will display the same component simultaneously.

B. Angular will throw an error because multiple unnamed router outlets are not allowed.

C. Only the first router outlet will work; the second will be ignored silently.

D. It will work fine and show different components automatically.

Solution

1. Step 1: Understand unnamed router outlet behavior

   Angular renders the primary route component in every unnamed <router-outlet> present in the template.

2. Step 2: Identify the problem

   Having two unnamed outlets means both will display identical component content, leading to duplication.

3. Final Answer:

   Both router outlets will display the same component simultaneously. -> Option A

4. Quick Check:

   Multiple unnamed outlets duplicate primary route [OK]

Hint: Multiple unnamed outlets show same component [OK]

Common Mistakes:

• Expecting an error from multiple unnamed outlets
• Thinking only the first outlet renders
• Believing outlets show different components automatically

5. You want to display a main view and a sidebar view simultaneously using Angular routing. How should you configure your template and routes to achieve this?

hard

A. Use only one <router-outlet> and load both components inside it.

B. Use two named <router-outlet name='main'></router-outlet> and <router-outlet name='sidebar'></router-outlet> in the template, and define routes with matching outlet names.

C. Use two unnamed <router-outlet></router-outlet> tags and define routes normally.

D. Use <router-outlet> for main view and manually insert sidebar component in template without routing.

Solution

1. Step 1: Use named router outlets in template

   To show multiple routed views simultaneously, each <router-outlet> must have a unique name attribute.

2. Step 2: Define routes with outlet names

   Routes must specify the outlet property matching the outlet names to load components into correct places.

3. Final Answer:

   Use two named <router-outlet> tags and define routes with matching outlet names. -> Option B

4. Quick Check:

   Named outlets + matching routes = multiple views [OK]

Hint: Name outlets and routes to show multiple views [OK]

Common Mistakes:

• Using multiple unnamed outlets for multiple views
• Trying to load multiple components in one outlet
• Not matching route outlet names with template