What specific challenges does Angular Elements solve when it comes to using Angular components in different environments?
- Cross-browser compatibility
- Framework agnosticism
- Handling dependency injection
- Handling global CSS styles
Angular Elements allows the use of Angular components in non-Angular environments, solving challenges related to framework agnosticism and enabling component reuse across different technologies.
How does Angular's router load a lazily-loaded module?
- By deferring loading
- By loading it immediately
- By preloading all modules
- By skipping the module
Angular's router loads a lazily-loaded module by deferring loading until it's needed, reducing the initial bundle size.
What is the main difference between Observables and Promises in Angular?
- Observables are synchronous
- Observables can emit multiple values
- Promises are used for HTTP requests
- Promises can be canceled
The main difference is that Observables can emit multiple values, whereas Promises can emit a single value and are not cancelable. Observables are more powerful for handling streams of data.
Imagine you have a directive that applies accessibility enhancements to elements. How would you test that the directive is correctly applying the necessary ARIA roles and attributes?
- Manually inspect HTML
- Use a screen reader
- Use end-to-end tests
- Use linters
To test the accessibility directive, you should manually inspect the generated HTML to ensure that it correctly applies the necessary ARIA roles and attributes. End-to-end tests may also help validate this behavior.
You have an Angular service that makes HTTP requests. During testing, you want to ensure that your service handles errors correctly. Which tool or technique would you use to simulate an HTTP error response?
- Angular HttpClient Mocking
- Angular TestBed
- Jasmine Spies
- Protractor End-to-End Testing
To simulate an HTTP error response during testing, you can use Angular HttpClient Mocking, which allows you to control HTTP responses in tests.
When creating a Route Resolver, it must implement the _____ interface.
- Resolve interface
- ResolveInterceptor
- Resolveable
- RouterResolver
When creating a Route Resolver, it must implement the Resolve interface. The Resolve interface defines a method to retrieve data for a route before it is activated.
The router-outlet directive acts as a _____ where the routed component is displayed.
- Container
- Directive
- Placeholder
- Router hub
The router-outlet directive acts as a placeholder where the routed component is displayed in Angular routing.
In Angular, using the _____ pipe can automatically handle subscription and unsubscription, preventing memory leaks.
- Async
- Observer
- Promise
- Subscribe
In Angular, using the Async pipe can automatically handle subscription and unsubscription, preventing memory leaks by managing the observable's lifecycle for you.
To create a custom directive that modifies the structure of the DOM, you would use a _____ directive.
- attribute
- component
- service
- structural
To modify the structure of the DOM, you would use a structural directive in Angular, such as ngFor or ngIf.
You need to implement a feature where clicking on a user's name in a list navigates to a detailed user profile page. The user ID needs to be passed in the URL. How would you implement this using Angular's router?
- Create a custom directive to handle the navigation and pass the user ID.
- Define a route with a parameter like /user/:userId and access the userId using ActivatedRoute.
- Store the user ID in a global service and retrieve it when navigating to the user profile page.
- Use a query parameter to pass the user ID in the URL and retrieve it using the QueryParams.
To navigate to a detailed user profile page with the user ID in the URL, you should define a route with a parameter like /user/:userId and access the userId using ActivatedRoute.