How can you override a provider for a service in a specific component or module?
- Using import and export statements
- Using providedIn property in @Injectable()
- Using providedIn property in @NgModule()
- Using the @Optional() decorator
To override a provider for a service in a specific component or module, you can use the providedIn property in @NgModule() to specify the provider at the module level.
How can you create a custom validator that depends on multiple form controls?
- Combine validators in a custom validation function
- Use a directive for form validation
- Use a reactive approach
- Use a template-driven approach
In Angular, you can create a custom validator that depends on multiple form controls by combining validators in a custom validation function. This allows you to implement complex validation logic that relies on the values of multiple form controls.
In Angular, the _____ method is used to assert that a certain expectation is met in tests.
- beforeEach
- describe
- expect
- it
The correct term to fill in the blank is expect. In Angular testing, you use the expect method from Jasmine to assert that a specific expectation is met during tests.
How can you ensure that a service provides a single, shared instance across an entire Angular application?
- Using a local provider in a component
- Using providedIn property
- Using the @Injectable() decorator
- Using the @Singleton() decorator
To ensure a service provides a single, shared instance across an entire Angular application, you can use the providedIn property in the @Injectable decorator and specify a module where the service should be provided. This ensures a singleton instance.
To selectively apply styles based on component logic, you can use ngClass binding in Angular.
- ngFor
- ngIf
- ngStyle
- ngSwitch
In Angular, the ngClass binding is used to selectively apply styles based on component logic by dynamically adding or removing CSS classes.
The _____ Subject will emit its most recent value to all subscribers whenever they subscribe.
- Async
- Behavior
- Multicast
- Replay
The Behavior Subject will emit its most recent value to all subscribers whenever they subscribe. It stores and shares the last emitted value among subscribers.
The _____ event is emitted when a navigation action starts.
- NavigationCancel
- NavigationEnd
- NavigationError
- NavigationStart
The blank should be filled with NavigationStart. The NavigationStart event is emitted when a navigation action starts in Angular.
The _____ operator is used to catch and handle errors within an Observable sequence.
- catchError
- filter
- map
- retry
The catchError operator is used to catch and handle errors within an Observable sequence. It allows you to gracefully handle errors in your observable stream.
In an e-commerce application, you need to create a checkout form that dynamically adds input fields based on the items in the user's cart. Which Angular concept can help you achieve this?
- Dynamic Component Creation
- One-way Data Binding with [ngModel]
- Router Guards for Dynamic Routing
- Service Injection
To dynamically add input fields based on cart items, you can use Dynamic Component Creation in Angular. This allows you to generate components on the fly based on user interactions.
How can you nest one component inside another in Angular?
- Using an ng-container
- Using ng-template
- Using structural directives
- Using the @ViewChild decorator
You can nest one component inside another in Angular by using the @ViewChild decorator to reference the child component within the parent.
You have a suite of E2E tests written using Protractor, and a particular test is flaky, occasionally failing without any code changes. What approach can you take to identify and resolve the issue?
- Debug the test
- Disable the test
- Rerun the test multiple times
- Rewrite the entire suite of tests
When encountering flaky tests in Protractor, the best approach is to debug the test to identify the root cause of the flakiness and make necessary adjustments. Rerunning the test multiple times or disabling it may not address the underlying problem. Rewriting the entire test suite is typically an overkill solution.
In Angular, how can you optimize form submission to prevent multiple submissions of the same data?
- Disable the submit button after the first click
- Implement server-side deduplication
- Use a unique key for each form submission
- Use debouncing techniques
In Angular, you can optimize form submission to prevent multiple submissions by disabling the submit button after the first click.