What is the main purpose of using directives in Angular applications?
- Create components
- Define routing
- Manipulate the DOM
- Modify data
The main purpose of using directives in Angular applications is to manipulate the DOM by adding, removing, or modifying elements and their behavior. Directives are used to extend HTML with new attributes and elements.
The method used to add a new form control to an existing Form Array is _____ .
- addControl
- addFormControl
- insertControl
- pushControl
The method used to add a new form control to an existing Form Array is addControl.
Components that are designed to be reusable across multiple parts of an application often implement the _____ lifecycle hook to do cleanup work.
- ngDoCheck
- ngOnChanges
- ngOnDestroy
- ngOnInit
Components that are designed to be reusable across multiple parts of an application often implement the ngOnDestroy lifecycle hook to do cleanup work, like unsubscribing from observables.
How does the @HostListener decorator enhance the functionality of a directive?
- Allows the directive to listen to events on the host element
- Binds data to HTML elements
- Defines component lifecycle hooks
- Enables routing in directives
The @HostListener decorator in Angular allows the directive to listen to events on the host element, enhancing its interactivity and behavior.
What is the purpose of the updateOn property when creating a new FormControl instance?
- It defines the initial control value
- It determines when the control is updated
- It sets the control's required state
- It specifies when to submit the form data
The updateOn property when creating a new FormControl instance in Angular specifies when the control is updated, which affects how and when the form data is updated and submitted.
When debugging a failing Protractor test, what tool can you use to pause the test execution and inspect the browser's state?
- Browser developer console
- Node.js debugger (e.g., DevTools)
- Protractor's built-in debugger
- WebDriver's built-in debugger (WDB)
When debugging a failing Protractor test, you can use the Node.js debugger, such as Chrome DevTools, to pause the test execution and inspect the browser's state.
To create an Observable that immediately completes without emitting any values, you can use the _____ function.
- create
- empty
- interval
- of
To create an Observable that immediately completes without emitting any values, you can use the empty function.
How does the merge operator behave when combining multiple Observables?
- It combines the latest values from all Observables.
- It emits values from all Observables as they arrive.
- It emits values from the first Observable only.
- It waits for all Observables to complete before emitting values.
The merge operator in RxJS emits values from all Observables as they arrive, without waiting for them to complete.
Angular Universal uses a technique known as _____ to handle asynchronous tasks on the server side.
- Client-Side Rendering
- Server-Side Rendering
- Service Workers
- Universal Injection
Angular Universal employs a technique known as Server-Side Rendering (SSR) to handle asynchronous tasks on the server side.
When you want to preload data for a route, you can use the _____ property in the route configuration.
- canActivate
- data
- loadChildren
- resolve
To preload data for a route, you can use the resolve property in the route configuration. The 'resolve' property allows you to fetch data before activating the route.