Which method of the ControlValueAccessor interface is called when the form control value changes programmatically?
- controlValueChanged()
- setValue()
- updateValue()
- writeValue()
The method of the ControlValueAccessor interface that is called when the form control value changes programmatically is writeValue(). This method allows you to update the form control's value from your custom form control component. It plays a crucial role in synchronizing the value between the custom control and the form group.
When you want to cancel a subscription to an Observable, you call the ________ method on the subscription object.
- cancel
- complete
- dispose
- unsubscribe
To cancel a subscription to an Observable and release its resources, you call the unsubscribe method on the subscription object. It's important to unsubscribe from Observables to prevent memory leaks when you're done using them.
What potential issue can arise when using Lazy Loading without properly planning the module structure?
- Circular dependencies
- Decreased maintainability
- Difficulty in routing configuration
- Increased initial loading time
When using Lazy Loading without proper planning, circular dependencies can arise. This occurs when two or more modules depend on each other, causing issues with module resolution and potentially leading to runtime errors. It's essential to structure modules carefully to avoid this problem.
Which method would you use in HttpInterceptor to catch and handle HTTP errors?
- catchError
- handleError
- handleError and catchError
- intercept
In an HttpInterceptor, you would use the intercept method to catch and handle HTTP errors. This method intercepts outgoing HTTP requests and incoming responses, giving you the opportunity to handle errors and modify requests before they are sent.
How can you analyze the bundle size of your Angular application?
- Using the "ng analyze" command
- Checking the browser console
- Using "npm start"
- Examining package.json
To analyze the bundle size of your Angular application, you can use the "ng analyze" command. This command provides detailed information about the size of each module and dependency in your application, helping you identify and optimize large bundles.
To make a service available only within a specific module, set the providedIn property to the ________ of that module.
- 'providers'
- 'imports'
- 'declarations'
- 'exports'
To limit the availability of a service to a specific module in Angular, you should set the 'providedIn' property to 'providers' of that module. This ensures that the service is scoped to the module where it's provided and can't be accessed outside of it. The other options ('imports,' 'declarations,' and 'exports') are unrelated to specifying service scope and purpose.
Which property of a FormControl instance would you check to determine if the user has interacted with a particular form control?
- dirty
- pristine
- touched
- untouched
To determine if the user has interacted with a particular form control in Angular Reactive Forms, you would check the touched property of the FormControl instance. It becomes true when the user has focused and blurred the form control, indicating interaction. The dirty property indicates if the value has changed.
How can you set default headers for every request made by HttpClient in your application?
- By adding headers to each HttpClient request manually
- By configuring HttpHeaders globally
- By modifying the HttpClient constructor
- By using an interceptor
You can set default headers for all HttpClient requests by using an interceptor. Interceptors allow you to intercept outgoing requests and modify them, including adding default headers, before they are sent.
Which of the following is the primary building block of an Angular application?
- Component
- Directive
- Module
- Service
In Angular, a component controls a patch of the screen called a view. Components are the main way to build and specify elements and logic on the page, making them the primary building block of an Angular application.
How can you set default values for form controls in a template-driven form?
- Use the defaultValue attribute.
- Assign values directly in the template.
- Set values programmatically in the component.
- Use the ngDefaultControl directive.
In template-driven forms, default values for form controls are typically set programmatically in the component by initializing the corresponding form control variables with the desired default values. While you can assign values directly in the template, this doesn't allow for dynamic default values or interaction with the component logic. The other options mentioned are not common practices for setting default values in template-driven forms.