In the context of state management in Angular, what is the role of "selectors"?
- Selectors are responsible for dispatching actions
- Selectors are used to derive data from the store
- Selectors handle side effects
- Selectors provide routing functionality
In Angular state management, "selectors" play a crucial role in deriving and transforming data from the store. They allow you to compute and return specific slices of the application state, making it easier to access and display relevant data in components.
Which option is NOT a valid view encapsulation mode in Angular?
- Emulated
- Shadow DOM
- None
- Native
In Angular, the valid view encapsulation modes are Emulated (default), Shadow DOM, and Native. The "None" option is not a valid view encapsulation mode. View encapsulation modes determine how Angular styles are applied and scoped in a component. "None" is not a recognized mode for Angular view encapsulation.
What is a potential drawback of not using lazy loading in larger applications?
- Increased memory usage
- Larger initial bundle size
- Reduced component reusability
- Slower application startup
Not using lazy loading in larger applications can result in a larger initial bundle size. This means that users need to download a bigger JavaScript file when they first access the application, which can lead to slower loading times, especially on slower network connections.
How can you achieve nested routing (child routes) within an Angular application?
- By defining child routes in the RouterModule
- By using Angular's loadChildren feature
- By using Angular's canActivateChild guard
- By applying a deep route nesting hierarchy
To achieve nested routing (child routes) in Angular, you define child routes within the RouterModule configuration. This allows you to create a hierarchical structure of routes. The other options relate to Angular's routing features but do not specifically address the process of achieving nested routes.
You are tasked with implementing a feature where, upon clicking a button, the user should be redirected to the home page. Which method or feature of Angular's router would you utilize?
- router.navigate(['/home']);
- router.navigate(['home']);
- router.navigateByUrl('/home');
- router.to(['/home']);
To redirect the user to the home page using Angular's router, you should use the router.navigate(['/home']); method. This method navigates to the specified route, in this case, '/home', which represents the home page. The other options are either incorrect or do not exist in Angular's routing syntax.
How can you project content from a parent component into a child component's template?
- Using structural directives like *ngFor.
- Using input properties.
- Using the ViewChild decorator.
- Using Angular modules.
You can project content from a parent component into a child component's template using structural directives like *ngFor, *ngIf, etc. These directives allow you to conditionally render or iterate over content in the child component's template based on data passed from the parent. Input properties are used to pass data, but they don't project content in this way. The other options are not related to content projection.
Imagine you have a modal component, and you want users to define custom header, body, and footer for each modal instance. How would you set up the modal component to achieve this?
- Use Angular Templates for Header, Body, and Footer
- Use ng-container for Header, Body, and Footer
- Use Angular Dynamic Components for Header, Body, and Footer
- Use ng-template for Header, Body, and Footer
To allow users to define custom header, body, and footer for each modal instance in Angular, you should use Angular Dynamic Components. This approach allows users to create and insert components dynamically at runtime, making it suitable for the scenario where custom content needs to be defined for each modal instance. While other options like templates, ng-container, and ng-template can be used for various purposes, they don't provide the same level of flexibility as dynamic components in this context.
What method of HttpClient would you use to send a GET request?
- delete()
- get()
- post()
- put()
To send a GET request using HttpClient, you would use the get() method. This method is used to perform HTTP GET requests to retrieve data from a specified URL.
If you have an application where some modules are loaded on-demand, and you want to restrict this based on user roles, which Route Guard should you implement?
- CanActivate
- CanActivateChild
- CanDeactivate
- CanLoad
To restrict loading of modules based on user roles in a lazy-loaded scenario, you should implement the CanLoad guard. It allows you to check conditions before the module is loaded, ensuring that only authorized users can access certain parts of the application.
Why would you use the ViewContainerRef in Angular?
- To manage the DOM elements where dynamic components are inserted.
- To create Angular services.
- To handle form submissions in Angular.
- To define Angular component templates.
ViewContainerRef in Angular is used to manage the DOM elements where dynamic components are inserted. It provides a reference to the container where you can dynamically add or remove components. This is useful for scenarios where you need to render components based on user interactions or application logic. The other options are not the primary purpose of ViewContainerRef.
What is the main purpose of Angular's ChangeDetectionStrategy.OnPush?
- To enable two-way data binding.
- To improve change detection performance.
- To disable change detection altogether.
- To increase the framework's size.
The main purpose of Angular's ChangeDetectionStrategy.OnPush is to improve change detection performance. When you use this strategy, Angular will only perform change detection when input properties of a component change or when certain events are triggered, leading to better performance in applications with complex component trees. The other options are not the main purpose of this strategy.
What does the term "Hierarchical Injector" refer to in Angular?
- A design pattern used to structure Angular components hierarchically.
- A type of dependency injection system in Angular that supports multiple hierarchies.
- An Angular feature that allows for dynamic component hierarchies.
- An Angular feature that automatically sorts components in a hierarchical order.
The term "Hierarchical Injector" in Angular refers to a type of dependency injection system that supports multiple hierarchies. In Angular, services can be provided at various levels of the application, and the hierarchical injector helps manage the scope and accessibility of these services. This is crucial for controlling how services are shared and instantiated within different parts of an Angular application.