How can you prevent an expression from being re-evaluated in every change detection cycle while using interpolation in Angular?
- Use a custom pipe
- Use ngOnPush change detection strategy
- Use one-time binding ({{::expression}})
- Use trackBy with ngFor directive
In Angular, you can prevent an expression from being re-evaluated by using one-time binding ({{::expression}}).
How can you convert a cold observable into a hot observable?
- Apply the "subscribe" method
- Implement the "map" operator
- Use the "share" operator
- Utilize the "take" operator
You can convert a cold observable into a hot observable by using the "share" operator, which allows multiple subscribers to receive the same values emitted by the observable simultaneously.
The [style.color] syntax in an Angular template is an example of _____ binding.
- Event
- Interpolation
- Property
- Two-way
The [style.color] syntax is an example of Property binding in Angular. It binds an element property (style.color) to a component property.
Angular provides the _____ function to define a sequence of animation steps.
- animate()
- bootstrap()
- ngIf
- subscribe()
Angular provides the animate() function to define a sequence of animation steps. This function is commonly used for creating animations in Angular.
When testing Angular services, you can replace a real service with a _____ to simulate service behavior.
- component
- mock
- pipe
- spy
When testing Angular services, you can replace a real service with a mock to simulate service behavior and control the service's responses for testing purposes.
Which operator can be used to automatically unsubscribe from an observable when a component is destroyed?
- "map" operator
- "subscribe" operator
- "takeUntil" operator
- "tap" operator
The "takeUntil" operator is commonly used to automatically unsubscribe from an observable when a component is destroyed. It takes an observable that emits when the component is destroyed, ensuring that the original observable is unsubscribed.
A directive that changes the appearance or behavior of a DOM element is known as a(n) _____ directive.
- attribute
- component
- decorator
- structural
A directive that changes the appearance or behavior of a DOM element is known as an attribute directive in Angular.
In a directive, the ________ decorator is used to get a reference to the host element.
- @Directive
- @HostBinding
- @HostListener
- @Injectable
In a directive, the @HostBinding decorator is used to get a reference to the host element, allowing you to access and modify its properties.
Reactive forms in Angular are also known as _____ forms.
- Data-driven forms
- Dynamic forms
- Model-driven forms
- Template forms
Reactive forms in Angular are also known as Model-driven forms, as they focus on creating the model and then binding it to the UI elements.
For testing dynamic behavior in directives, such as responding to user input or changes in data, you can use _______.
- Jasmine
- Mocks
- Spies
- TestBed
To test dynamic behavior in directives, you can use Jasmine for its testing capabilities, including spies for tracking function calls.