Hierarchical Dependency Injection in Angular means that if you request a service from an injector, it will retrieve it from the current injector or from any of its _____ injectors.
- Child
- Parent
- Root
- Sibling
In Angular, Hierarchical Dependency Injection means that if you request a service from an injector, it will retrieve it from the current injector or from any of its Parent injectors.
The process of initializing data properties of a component just before it's displayed is done in the _____ lifecycle hook.
- ngAfterViewInit
- ngInit
- ngOnChanges
- ngOnInit
The process of initializing data properties of a component just before it's displayed is done in the ngOnInit lifecycle hook.
To asynchronously validate a form control value, you can use a _____ validator.
- asyncValidator
- mergeMap
- subscribe
- syncValidator
To asynchronously validate a form control value in Angular, you can use an asyncValidator.
In Angular, developers can use the _____ service to log errors to the console during debugging.
- Console
- Error
- Http
- Log
In Angular, developers can use the Error service to log errors to the console during debugging, making it easier to diagnose issues.
You're experiencing a situation where your Angular application works as expected during development but breaks when running unit tests. What steps can you take to identify and rectify the discrepancy?
- Analyze environment differences
- Check for asynchronous code
- Debug the failing unit tests
- Increase unit test coverage
To identify and rectify the discrepancy between development and unit tests, you should analyze environment differences that might be affecting the tests.
You need to build a form that fetches and populates its options (e.g., a dropdown list) from an API. Which form approach would allow you more flexibility and control over handling data asynchronously?
- Template-driven forms
- Reactive forms
- Both provide the same flexibility
- None of the above
To handle data asynchronously and fetch options from an API, Reactive forms would be the better choice as they offer more flexibility and control over handling asynchronous data.
In template-driven forms, the _____ directive is used to create two-way data bindings on an input field.
- *ngFor
- *ngIf
- *ngModel
- *ngSwitch
In template-driven forms, the *ngModel directive is used to create two-way data bindings on an input field, allowing the field to sync its value with a component property.
You are building a form where certain fields need to be shown or hidden based on the selection of a dropdown. How can you dynamically add or remove validations on these fields based on their visibility?
- Create separate forms for each combination of visible fields.
- Use ngClass to toggle validations dynamically.
- Use ngSwitch to toggle validations based on the dropdown value.
- Use the ngIf directive to conditionally add or remove validators.
To dynamically add or remove validations on fields based on their visibility in an Angular form, you should use the ngIf directive to conditionally add or remove validators. This approach allows for dynamic validation based on UI interactions.
You're working on an application that has several feature modules. To improve the user experience, you decide to preload some modules in the background while the user is interacting with the app. How can you implement this behavior?
- Manually load modules using import() as the user interacts with different parts of the app
- Use localStorage to cache module data and preload them when the app loads
- Use the Angular Router Preloading Strategy to preload specific modules
- Utilize a service worker to cache and preload modules as a background process
To improve the user experience by preloading specific modules in the background as the user interacts with the app, you can use the Angular Router Preloading Strategy. It allows you to preload modules when needed, optimizing the app's performance.
How do you track the validity and state of a form control in a template-driven form?
- Using *ngIf directive
- Using [(ngModel)] directive
- Using [formControl] directive
- Using [formState] directive
To track the validity and state of a form control in a template-driven form, you can use the [formControl] directive, which binds the control's state and validity to the template.
To set up the testing environment before running any test suite in Protractor, you can utilize the _____ function in the configuration file.
- beforeAll
- browser.driver
- onCleanup
- onPrepare
To set up the testing environment before running any test suite in Protractor, you can use the onPrepare function in the configuration file.
When a navigation fails due to an unexpected error, Angular fires the _____ event.
- NavigationCancel
- NavigationEnd
- NavigationError
- NavigationStart
When a navigation fails due to an unexpected error, Angular fires the NavigationError event. This event is triggered when there is an error during navigation.