In what scenario might you need to use both ComponentFactoryResolver and ViewContainerRef together?
- When creating a dynamic form with user-generated fields.
- When applying CSS styles to a component.
- When handling HTTP requests in Angular.
- When using Angular animations in a component.
You might need to use both ComponentFactoryResolver and ViewContainerRef together when creating a dynamic form with user-generated fields. ComponentFactoryResolver is used to dynamically create components for each form field, and ViewContainerRef is used to manage the location where these components are inserted within the DOM. This combination allows you to dynamically generate and manage form fields based on user input or requirements. The other options do not typically require both ComponentFactoryResolver and ViewContainerRef together.
For which purpose might you consider using dynamic components in Angular?
- Defining application routes
- Lazy loading of modules
- Optimizing database queries by default
- Styling components dynamically
Dynamic components in Angular are often used for lazy loading of modules. This allows you to load parts of your application on-demand, improving initial loading times and overall performance. While Angular uses routes to define application navigation, dynamic components are not used for this specific purpose. They are also not primarily used for styling components dynamically or optimizing database queries.
Your team is building a custom slider component, and you want to make sure it can be used inside Angular forms, both reactive and template-driven. What steps are necessary to achieve this?
- Add the slider component to the Angular template and use two-way data binding.
- Create a custom Angular form control and integrate it with the slider component.
- Use JavaScript event listeners to capture slider changes and update form values.
- Wrap the slider component in a separate Angular module.
To make a custom slider component compatible with Angular forms (both reactive and template-driven), you should create a custom Angular form control and integrate it with the slider component. This involves creating a control that manages the slider's value and state, allowing you to use it within Angular forms. Simply adding the component to the template and using two-way data binding may not provide the necessary form control features. Using event listeners directly is not the recommended approach in Angular. Wrapping the component in a module alone won't make it work with forms.
Dependency injection in Angular is primarily driven by the ________ mechanism.
- 'decorator'
- 'dependency'
- 'injection'
- 'singleton'
Dependency injection in Angular is primarily driven by the 'dependency' mechanism. Angular's dependency injection system is responsible for providing instances of services or other dependencies to components and services that request them. The 'dependency' mechanism ensures that components receive the correct instances of their dependencies, making it a core concept in Angular's architecture.
What is the primary purpose of Ahead-of-Time (AOT) Compilation in Angular?
- Easier debugging
- Enhanced developer experience
- Improved runtime performance
- Reduced code maintainability
The primary purpose of Ahead-of-Time (AOT) Compilation in Angular is improved runtime performance. AOT compiles Angular templates and components during the build process, resulting in faster rendering and smaller bundle sizes when compared to Just-in-Time (JIT) Compilation.
If you want to handle an Observable that emits multiple values over time but you're only interested in the latest value when another Observable emits, which operator would you use?
- combineLatest
- exhaustMap
- mergeMap
- switchMap
To handle an Observable that emits multiple values over time but only get the latest value when another Observable emits, you would use the combineLatest operator. It combines the latest values from multiple Observables whenever any of them emits a new value.
The mechanism that allows you to inject content from a parent component into a child component's view is known as ________.
- Propagation
- Data binding
- Content projection
- Component interaction
Content projection is the mechanism that enables you to inject content from a parent component into a child component's view. It is commonly used in frameworks like Angular to pass content from a parent component to specific slots in a child component. Options 1, 2, and 4 are not accurate descriptions of this mechanism.
What is the primary use of the HttpClient module in Angular?
- Handling form submissions
- Making HTTP requests to a server
- Managing component state
- Rendering UI components
The primary use of the HttpClient module in Angular is to make HTTP requests to a server. It provides a convenient way to interact with APIs and retrieve data from remote sources, such as RESTful services. HttpClient simplifies tasks like GET, POST, PUT, and DELETE requests and allows you to handle responses and errors effectively.
What's the primary use of the Renderer2 class in custom directives?
- Defining custom pipes.
- Handling HTTP requests.
- Managing form controls.
- Manipulating the DOM directly.
The primary use of the Renderer2 class in custom directives is to manipulate the DOM directly. It provides a safer and more platform-agnostic way to interact with the DOM, ensuring that changes are rendered consistently across different platforms and environments. It's essential for making dynamic changes to the DOM within Angular applications.
Which object is responsible for tracking the value and validation status of an individual form control in reactive forms?
- FormArray
- FormControl
- FormField
- FormGroup
In reactive forms in Angular, the FormControl object is responsible for tracking the value and validation status of an individual form control. It represents a single input field and provides various methods and properties to manage its value and validation. FormArray and FormGroup are used for managing collections of controls or nested groups of controls, but FormControl is used for individual controls.