What is the main benefit of using child routes in Angular applications?
- Creating shared services
- Handling HTTP requests
- Lazy loading components
- Navigating to the parent
The main benefit of using child routes in Angular is lazy loading components, which improves performance by loading components on demand.
You have an Observable stream of user actions in your application. You want to perform a side effect, such as logging, each time an action occurs without modifying the original stream. Which RxJS operator should you use?
- do (or tap)
- filter
- map
- take
When you want to perform side effects on an observable stream without modifying the data, you should use the do (or tap) operator. This allows you to perform actions like logging or debugging without altering the original stream.
When creating a custom pipe, implementing the _____ interface ensures that the pipe recalculates only when the input values change.
- DynamicPipe
- OnChanges
- PipeTransform
- PipeUpdate
When creating a custom pipe in Angular, implementing the PipeTransform interface ensures that the pipe recalculates only when the input values change.
In a reactive form, the _____ method is used to update the value of a form control programmatically.
- patchValue()
- reset()
- setValue()
- updateValueAndValidity()
In a reactive form, the patchValue() method is used to update the value of a form control programmatically. This method allows you to set specific control values.
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.
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.