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.
You are building a shopping cart application using Angular and NgRx. You want to display a smooth animation when items are added to the cart. How would you implement this?
- Use Angular's @HostListener decorator to listen for events and create animations in response to user actions.
- Use Angular's built-in ng-animate directive to create the animation and dispatch a custom action in NgRx to control it.
- Use the @ngrx/effects library to handle animations asynchronously and dispatch an action to trigger the animation.
- Use the @ngrx/router-store library to handle route changes and trigger animations when the route changes.
To implement smooth animations when items are added to the cart in an NgRx-based Angular application, you can use the @ngrx/effects library to handle animations asynchronously. By dispatching an action to trigger the animation, you can ensure smooth and non-blocking animations in the shopping cart.
What is the purpose of the ngOnInit lifecycle hook in an Angular component?
- To destroy the component
- To handle HTTP requests and API calls
- To initialize component properties
- To subscribe to observables
The ngOnInit lifecycle hook is used to initialize component properties and perform any setup needed when a component is created.
How can you create a custom attribute directive in Angular?
- By configuring a module
- By extending a class
- Using a service
- Via an HTML element
You can create a custom attribute directive in Angular by extending a class and implementing the necessary logic.
How can you implement a custom form control that works seamlessly with Form Groups and Form Arrays?
- Create a custom component-based form control
- Extend the AbstractControl class
- Implement a custom validator function
- Use the FormBuilder service to create the control
To implement a custom form control that works seamlessly with Form Groups and Form Arrays in Angular, you should create a custom component-based form control.
You have a directive that changes the background color of an element when the user hovers over it. How would you test this directive to ensure that it behaves correctly?
- Use end-to-end tests
- Use linters
- Use unit tests
- Use visual regression tests
To test this directive, you should use unit tests. Unit tests are suitable for testing the individual behavior of the directive and verifying that it changes the background color on hover as expected.
Which RxJS operator is used to transform the items emitted by an Observable?
- map
- of
- pipe
- subscribe
The correct RxJS operator used to transform the items emitted by an Observable is map. It allows you to apply a function to each emitted item and return the transformed item.
What is the impact of lazy loading on the initial load time of an Angular application?
- It depends on the module
- It has no impact
- It increases initial load
- It reduces initial load
Lazy loading has a positive impact on the initial load time of an Angular application as it reduces the initial load by loading modules on-demand.
You are tasked with implementing a sign-up form where the password field must match the confirm password field. Which approach would you use to validate this in Angular?
- Built-in Validators
- Custom Validator Function
- Service-based Validation
- Two-way data binding with ngModel
To validate that the password and confirm password fields match, you should use a Custom Validator Function in Angular to implement custom validation logic.
You are optimizing an Angular application and want to ensure that the generated code is as small as possible for faster load times. How can the Ivy Renderer assist in achieving this goal?
- Better component encapsulation
- Enhanced routing performance
- Faster compilation
- Improved tree-shakability
The Ivy Renderer assists in generating smaller code by improving tree-shakability. Tree shaking eliminates unused code during the build process, resulting in a smaller bundle size for faster loading times.
What is the primary use of "spy" functions in Jasmine?
- To generate random data for testing
- To log console output
- To monitor and track function calls
- To suppress error messages during tests
The primary use of "spy" functions in Jasmine is to monitor and track function calls during tests, enabling you to check how functions are called and with what arguments.
In Angular, what does a pipe do?
- Create components and services
- Manage state and business logic
- Route navigation and URL management
- Transform and format data
In Angular, a pipe is used to transform and format data in templates. Pipes are built-in or custom functions for modifying how data is displayed in the view.