Which method of the ControlValueAccessor interface is called to write a new value from the form model into the view?
- writeValue
- registerOnChange
- registerOnTouched
- setViewValue
In the context of the ControlValueAccessor interface in Angular, the writeValue method is responsible for writing a new value from the form model into the view. This method is used to update the UI with the latest value when there are changes in the underlying data model. The other options (registerOnChange, registerOnTouched, setViewValue) have different responsibilities related to handling form control interactions but are not used for updating the view with new values.
When setting up routing in Angular, where do you usually define the paths and their associated components?
- In a separate routing module file.
- In the app.component.ts file.
- In the app.module.ts file.
- In the index.html file.
In Angular, paths and their associated components are typically defined in a separate routing module file. This separation helps organize and manage routing configurations more effectively. While it's possible to define routes in other files, the recommended and conventional approach is to use a dedicated routing module.
Which attribute can be added to a form control to make it required?
- [ngRequired]
- [required]
- [validate]
- [isRequired]
In template-driven forms, the [required] attribute can be added to a form control to make it required. When this attribute is present on an input element, the user must fill in the control before submitting the form. It's a simple way to implement basic form validation for mandatory fields. The other options are not standard attributes for making form controls required in Angular template-driven forms.
In the context of NgRx, when an action is dispatched, it is processed by a ________ to produce a new state.
- Effect
- Middleware
- Reducer
- Selector
In the context of NgRx, when an action is dispatched, it is processed by a "Reducer" to produce a new state. Reducers are pure functions that specify how the state should change based on the action type and payload.
What's the purpose of the FormBuilder service in Angular's reactive forms?
- It's used for styling forms with CSS.
- It's used to create form controls manually.
- It's used to handle HTTP requests in forms.
- It's used to simplify the creation of form controls.
The FormBuilder service in Angular's reactive forms is used to simplify the creation of form controls and form groups. It provides a more concise and readable way to define form structures compared to manually creating controls. While Angular also uses HTTP for handling HTTP requests in forms, this is not the primary purpose of FormBuilder. It's primarily focused on form control management.
A backend API endpoint occasionally fails, and you want to implement a strategy to retry the request three times before giving up. How would you achieve this in Angular?
- Implement a custom retry mechanism in a service
- Set the maxRetries configuration option in Angular HTTP Client
- Use a timeout for three retries in the catch block
- Use the RxJS retry operator with a count of 3
To implement a strategy to retry an HTTP request three times before giving up in Angular, you should use the RxJS retry operator with a count of 3. This operator allows you to specify the number of retry attempts for a failed request, helping you achieve the desired retry behavior.
To define specific styles that apply only to a component and do not affect any external elements, you'd set the component's encapsulation property to ViewEncapsulation.______.
- None
- ShadowDom
- Emulated
- Native
In Angular, the encapsulation property determines how styles are scoped for a component. Setting it to Emulated (or None for no encapsulation) ensures that styles apply only to the component and its descendants, not affecting external elements. This is often used to create encapsulated styles for Angular components. The other options (ShadowDom and Native) represent different encapsulation methods, but Emulated is the correct option for this scenario.
Which command or flag should you use with Angular CLI if you want to analyze the size of your bundles?
- "ng analyze"
- "ng build --stats-json"
- "ng bundle-analysis"
- "ng size-check"
To analyze the size of your bundles in an Angular application, you should use the "ng analyze" command. This command provides detailed information about the size of your application's bundles, including dependencies and modules.
A service provided at the component level will create a new instance for each ________ of the component.
- 'child component'
- 'function'
- 'instance'
- 'module'
A service provided at the component level will create a new instance for each 'instance' of the component. This means that every time a new instance of the component is created, a new instance of the service will also be created, ensuring that each component instance has its own isolated instance of the service.
Which operator is best suited for handling multiple click events in rapid succession with RxJS in Angular?
- debounceTime()
- filter()
- map()
- switchMap()
The debounceTime() operator in RxJS is best suited for handling multiple click events in rapid succession. It allows you to specify a time window during which it will ignore subsequent events, which is ideal for scenarios where you want to debounce click events to avoid processing them too quickly. The other operators have different use cases and are not specifically designed for this scenario.