You are building an e-commerce application. On the product page, you want to have tabs for "Details", "Reviews", and "Related Products", each being a separate route. How would you structure this in Angular?
- Create child routes for each tab within the product page route
- Create separate components for each tab and load them dynamically
- Use one route and manage tab switching with ngIf
- Use route guards to load content on demand
In this scenario, it's best to create child routes for each tab within the product page route. This approach allows you to have separate components and templates for each tab while maintaining a clean URL structure.
The process of retrieving previous navigation details, such as the previously visited route, can be achieved using router.________ in Angular.
- router.events
- router.history
- router.previousRoute
- router.snapshot
In Angular, the process of retrieving previous navigation details, including the previously visited route, can be achieved using router.events. This is because router.events emits events related to route navigation, including NavigationEnd events, which can be used to access the previous route or URL and implement custom logic based on it.
You have a component that receives a large list of items as an input. You notice performance degradation when items within this list are updated frequently. Which change detection strategy would be most appropriate to address this?
- OnPush Change Detection
- Default Change Detection
- CheckAlways Change Detection
- Detached Change Detection
In this scenario, when dealing with frequent updates to a large list of items, using the OnPush change detection strategy is most appropriate. It allows the component to only re-render when its input properties change or when explicitly triggered, which can significantly improve performance by reducing unnecessary updates. Default change detection (Option 2) checks for changes on every digest cycle, leading to performance issues in this scenario. CheckAlways (Option 3) and Detached (Option 4) are not recommended for typical use cases.
Which directive is utilized to switch between multiple views, but only one view can be displayed at a time?
- *ngFor
- *ngIf
- *ngModel
- *ngSwitch
The *ngSwitch directive in Angular is used to switch between multiple views, but only one view can be displayed at a time based on a specified condition. It's commonly used for rendering different templates or components depending on the value of an expression. The other directives listed, such as *ngFor, *ngIf, and *ngModel, have different purposes and don't provide the same view-switching behavior.
When dynamically creating a component, which object is responsible for providing the factory to create an instance of the component?
- ComponentFactoryResolver
- ElementRef
- NgModule
- ViewChild
The ComponentFactoryResolver is responsible for providing the factory to create an instance of a component dynamically in Angular. It's a crucial part of dynamic component creation, allowing you to create components on the fly based on specific conditions or requirements in your application. NgModule deals with module-level configuration, ViewChild is used for querying child components, and ElementRef is used for accessing the DOM element of a component, but none of these directly provide a factory for dynamic component creation.
To apply styles scoped to a particular component and prevent them from affecting other elements outside the component, you would use _____.
- ::ng-deep
- ViewEncapsulation.Emulated
- ViewEncapsulation.None
- ng-deep
To apply styles scoped to a particular component in Angular and prevent them from leaking out and affecting other elements, you would use the ::ng-deep selector. This is used to pierce through the view encapsulation and apply styles to specific components.
For handling multiple values over time in Angular, you would use ________ instead of Promises.
- Components
- Decorators
- Modules
- Observables
In Angular, when you need to handle multiple values over time, you should use Observables instead of Promises. Observables are more versatile and allow you to work with asynchronous data in a more flexible manner. They can emit multiple values, making them ideal for scenarios like handling streams of data from HTTP requests or user interactions.
You have a multi-step registration process where each step is its own route. A user should not proceed to the next step without completing the previous one. How would you enforce this in Angular?
- Implementing route guards to prevent navigation to the next step until the current step is completed.
- Using conditional statements to hide the next step until the current step is completed.
- Storing step completion status in a browser cookie and checking it during navigation.
- Reloading the page after each step to ensure step completion.
In Angular, you can enforce the requirement that a user should not proceed to the next step without completing the previous one by implementing route guards. Route guards are Angular's way of protecting routes and can be used to prevent navigation until certain conditions, such as step completion, are met. The other options are not recommended practices for enforcing this requirement in an Angular application.
How does Akita differ in its approach to state management compared to NgRx?
- Employs Redux-style pattern with actions and reducers
- Favors a component-based state management approach
- Uses a simpler, more declarative approach
- Utilizes MobX for reactive state management
Akita differs from NgRx by using a simpler and more declarative approach to state management. It provides a straightforward way to manage state in Angular applications without the boilerplate associated with Redux-style patterns.
You have a shared service that maintains user settings. You notice that different parts of the application have different instances of this service. What could be a possible reason?
- Different parts of the application are using different configurations, which require separate instances of the service.
- The application is not using a proper dependency injection framework.
- The shared service is being loaded with lazy loading modules, leading to multiple instances.
- There is a bug in the shared service causing it to create multiple instances.
Different parts of the application may require different configurations or data, which necessitates separate instances of the shared service. This allows each part of the application to have its own instance with specific settings or configurations. It's not a bug or dependency injection issue but rather a design choice to accommodate varying requirements.