Angular Universal overview - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

What is the primary benefit of Angular Universal?

Angular Universal allows Angular apps to be rendered on the server. What is the main advantage of this?

A Automatically converts Angular apps into desktop applications

B Allows Angular apps to run without a browser

C Enables Angular apps to use native mobile device features

D Improves initial page load speed and SEO by rendering pages on the server

💡 Hint

Think about what happens before the browser fully loads the app.

Angular Universal renders the app on the server first, so users see content faster and search engines can index pages better.

❓ component_behavior

intermediate

How does Angular Universal affect component lifecycle hooks?

When using Angular Universal, which lifecycle hook runs only in the browser and not during server-side rendering?

A ngOnInit

B ngAfterViewInit

C ngOnChanges

D ngDoCheck

💡 Hint

Think about hooks that depend on the browser DOM.

ngAfterViewInit runs after the component's view is fully initialized, which requires the browser DOM and does not run during server-side rendering.

📝 Syntax

advanced

Identify the correct way to detect server vs browser in Angular Universal

Which code snippet correctly detects if the app is running on the server or in the browser?

Angular

import { PLATFORM_ID, Inject } from '@angular/core';
import { isPlatformBrowser, isPlatformServer } from '@angular/common';

constructor(@Inject(PLATFORM_ID) private platformId: Object) {
  // Detect platform here
}

A if (isPlatformServer(this.platformId)) { console.log('Browser'); } else { console.log('Server'); }

B if (this.platformId === 'browser') { console.log('Browser'); } else { console.log('Server'); }

C if (isPlatformBrowser(this.platformId)) { console.log('Browser'); } else { console.log('Server'); }

D if (this.platformId === 'server') { console.log('Browser'); } else { console.log('Server'); }

💡 Hint

Use Angular's helper functions for platform detection.

Angular provides isPlatformBrowser and isPlatformServer to detect the running platform using PLATFORM_ID.

🔧 Debug

advanced

Why does this Angular Universal app fail to render on the server?

Given this code snippet, why does the server-side render fail? constructor() { window.alert('Hello'); } Options:

A window is undefined on the server, causing a runtime error

B alert is not a function in Angular Universal

C Constructor cannot contain any code in Angular Universal

D The code should use document instead of window

💡 Hint

Remember what objects exist only in the browser environment.

The window object does not exist on the server, so accessing it causes an error during server-side rendering.

❓ state_output

expert

What is the output of this Angular Universal server-side rendered component?

Consider this Angular component code: @Component({ selector: 'app-counter', template: `

Count: {{ count }}

` }) export class CounterComponent { count = 0; constructor() { this.increment(); } increment() { this.count += 1; } } What will be the rendered HTML output on the server?

A <p>Count: 1</p>

B <p>Count: 0</p>

C <p>Count: undefined</p>

D <p>Count: NaN</p>

💡 Hint

Check when the increment method runs relative to rendering.

The constructor calls increment(), which adds 1 to count before rendering, so the output is Count: 1.