The @Output() decorator is used to emit custom ________ from a component.
- input events
- methods
- output events
- properties
The @Output() decorator is used to emit custom output events from an Angular component. These events allow a component to communicate with its parent or containing components. By emitting custom events, a child component can notify its parent about specific actions or changes, enabling parent-child communication in Angular applications.
Which state management solution is based on the concept of stores and queries?
- Akita
- MobX
- Redux
- RxJS
Akita is based on the concept of stores and queries. In Akita, stores hold the application state, and queries are used to retrieve and manipulate data from these stores. This pattern makes state management in Akita efficient and intuitive.
A client asks you to highlight the currently active page link in the navigation menu. How would you achieve this in Angular?
- By using the routerLinkActive directive and applying it to the navigation menu items with a CSS class.
- By using JavaScript to detect the active route and apply a CSS class to the corresponding navigation menu item.
- By manually updating the active page link in the navigation component whenever a route changes.
- By creating a custom Angular directive to handle active link highlighting.
To highlight the currently active page link in the navigation menu in Angular, you should use the routerLinkActive directive. This directive is applied to the navigation menu items and automatically adds a CSS class when the corresponding route is active. The other options are either incorrect or involve more manual and error-prone approaches.
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.
When creating a custom attribute directive, which decorator is used to define its metadata?
- @Component
- @Directive
- @Attribute
- @Metadata
In Angular, to create a custom attribute directive, you use the @Directive decorator to define its metadata. This decorator allows you to specify the selector, inputs, outputs, and other properties that determine how the directive behaves when applied to elements in the DOM. The other options, such as @Component, @Attribute, and @Metadata, are not typically used for creating attribute directives.
How does the ChangeDetectionStrategy.OnPush improve performance in Angular components?
- It enables two-way data binding
- It forces constant change detection
- It prevents data mutation
- It reduces the frequency of change detection cycles
The ChangeDetectionStrategy.OnPush setting in Angular tells the framework to perform change detection only when the inputs to a component change, rather than after every event. This optimization reduces the frequency of change detection cycles, which can significantly improve performance, especially in complex applications.
Which Angular CLI command helps in updating your Angular application to the latest version?
- ng migrate
- ng refresh
- ng update
- ng upgrade
The ng update command in Angular CLI is used to update your Angular application to the latest version of Angular and its dependencies. It helps you keep your application up-to-date with the latest features, bug fixes, and security patches.
When setting up routes in an Angular application, which property in the route configuration determines the component that should be displayed?
- component
- displayComponent
- loadChildren
- routeComponent
In Angular routing, the 'component' property in the route configuration is used to determine which component should be displayed when the route is activated. This is where you specify the component class that corresponds to the route. The 'component' property plays a fundamental role in defining the view associated with a route.
In Jasmine, what function is used to group together related test cases?
- afterEach()
- beforeAll()
- describe()
- it()
In Jasmine, the describe() function is used to group related test cases together. It provides a way to organize and structure your test suite by grouping individual test specs within a larger block. This helps in better test organization and readability.