Which feature in Angular allows you to create custom HTML elements that can be used outside Angular applications?
- Angular Components
- Angular Elements
- Angular Modules
- Angular Services
The feature in Angular that allows you to create custom HTML elements usable outside Angular applications is Angular Elements.
You are tasked with optimizing an Angular application's load time. One strategy is to minimize the number of services that are eagerly loaded. Which technique can help achieve this?
- Using 'ngFor' directive
- Using 'ngIf' directive
- Using the 'async' pipe
- Using the 'providedIn' property
To minimize the number of services that are eagerly loaded in an Angular application, you can use the 'providedIn' property to specify that a service should be lazily loaded, which can improve load time.
When you want to execute a side effect for every emission on the source Observable, but return an Observable that is identical to the source, you can use the _____ operator.
- finalize
- reduce
- subscribe
- tap
When you want to execute a side effect for every emission on the source Observable, but return an Observable that is identical to the source, you can use the tap operator.
When testing a directive, which testing utility can be used to interact with a directive's host element?
- ComponentFixture
- DebugElement
- TestBed
- TestHostDirective
In Angular testing, you can use the DebugElement to interact with a directive's host element, query elements, and trigger events.
In an Angular application, how can you optimize a component to be checked only once by Angular's change detection mechanism?
- Use the Default change detection strategy
- Use the EventEmitter to trigger change detection
- Use the OnPush change detection strategy
- Use the Renderer2 to skip change detection
To optimize a component to be checked only once by Angular's change detection, you should use the OnPush change detection strategy. This strategy reduces unnecessary checks.
You're building a type-ahead search feature in an Angular application. The user input should trigger API calls, but you want to avoid making unnecessary calls for every keystroke. Which RxJS operators can help optimize this?
- filter and reduce
- mergeMap and throttleTime
- switchMap and debounceTime
- take and pluck
To optimize the type-ahead search feature, you can use switchMap to cancel previous API calls and only return the latest result, and debounceTime to delay the API call until the user stops typing, avoiding unnecessary calls for every keystroke.
What language is used to write E2E tests in Protractor?
- Java
- JavaScript
- Python
- TypeScript
JavaScript is the language used to write E2E tests in Protractor, making it compatible with Angular applications, as Angular also uses JavaScript.
Which Router Event can be used to perform actions after a navigation has successfully completed?
- NavigationCancel
- NavigationEnd
- NavigationError
- NavigationStart
To perform actions after a navigation has successfully completed, you can use the NavigationEnd event from the Router events.
Which Angular CLI command is used to generate a new component?
- ng create component
- ng generate component
- ng make component
- ng new component
To generate a new component in Angular using the CLI, you use the ng generate component command.
What is the significance of the declarations array in an Angular module?
- To configure route paths
- To declare components in the module
- To define component dependencies
- To set up HTTP interceptors
The declarations array in an Angular module is used to declare components that are part of the module. This is important for Angular to know which components are available within the module.