Which decorator is used to define a custom directive in Angular?
- @Component
- @Directive
- @Injectable
- @NgModule
To define a custom directive in Angular, you use the @Directive decorator.
In Angular, what is the purpose of using animations?
- Better security
- Enhanced code readability
- Improved user experience
- Simplified routing
The purpose of using animations in Angular is to provide an improved user experience by adding visual effects and transitions to the application, making it more engaging and user-friendly.
When creating dynamic forms, you can bind form controls to data using the _____ property.
- FormArray
- FormControlArray
- FormGroup
- FormModel
When creating dynamic forms in Angular, you can bind form controls to data using the FormGroup property.
You are writing a test for a component that has a dependency on a service. The service has a method that returns an observable. You want to test how the component behaves when the observable emits a value. What would be the best approach to take?
- Manually Creating Observables and Subscribing to them
- Replacing Observables with Promises in the component
- Testing the component without involving the service
- Using RxJS Marble Diagrams to control observable emissions
The best approach for testing how a component behaves when an observable emits values is to use RxJS Marble Diagrams. They allow you to control and simulate the observable emissions in a predictable way.
You are building a real-time chat application and need to ensure that all components displaying chat messages are updated instantly when a new message arrives. Which RxJS entity would be most suitable for this task?
- BehaviorSubject
- Observable
- ReplaySubject
- Subject
In this scenario, Subject is the most suitable choice. Subjects act as both Observers and Observables, making them perfect for handling real-time updates in a chat application, as they can multicast messages to all subscribers.
Which command is used to install Angular Universal in an existing Angular project?
- ng add @angular/universal
- ng add @nguniversal/express-engine
- ng add universal
- ng install angular-universal
To install Angular Universal in an existing Angular project, you use the command ng add @nguniversal/express-engine.
How can you test an Angular component that depends on a service with asynchronous methods?
- Manually delay the test execution with setTimeout
- Use Jasmine's done function
- Use the fakeAsync and tick functions
- Utilize the async and await keywords
In Angular testing, you can test a component with asynchronous service dependencies by using the **fakeAsync** and **tick** utilities. These allow you to handle asynchronous operations in a controlled manner during testing. The done function, async/await, and setTimeout are less suitable for this purpose.
What is the primary use of custom validators in Angular forms?
- Applying CSS styles
- Controlling routing and navigation
- Enhancing user interface
- Performing data validation
The primary use of custom validators in Angular forms is for performing data validation. Custom validators are used to check and ensure the validity of user input.
For a form control, setting the _____ property ensures that the validation status is updated only when the control loses focus.
- markAsTouched
- updateOn
- updateValueAndValidity
- validator
In Angular, setting the updateOn property for a form control ensures that the validation status is updated only when the control loses focus.
What is the primary purpose of Angular Elements?
- Create custom modules
- Create reusable web components
- Enable server-side rendering
- Extend Angular applications
The primary purpose of Angular Elements is to create reusable web components that can be used outside Angular applications.