Which feature in Angular allows you to create custom HTML elements that can be used outside Angular applications?
- Angular Components
- Angular Elements
- Angular Modules
- Angular Services
The feature in Angular that allows you to create custom HTML elements usable outside Angular applications is Angular Elements.
You are tasked with optimizing an Angular application's load time. One strategy is to minimize the number of services that are eagerly loaded. Which technique can help achieve this?
- Using 'ngFor' directive
- Using 'ngIf' directive
- Using the 'async' pipe
- Using the 'providedIn' property
To minimize the number of services that are eagerly loaded in an Angular application, you can use the 'providedIn' property to specify that a service should be lazily loaded, which can improve load time.
When you want to execute a side effect for every emission on the source Observable, but return an Observable that is identical to the source, you can use the _____ operator.
- finalize
- reduce
- subscribe
- tap
When you want to execute a side effect for every emission on the source Observable, but return an Observable that is identical to the source, you can use the tap operator.
What is the significance of the declarations array in an Angular module?
- To configure route paths
- To declare components in the module
- To define component dependencies
- To set up HTTP interceptors
The declarations array in an Angular module is used to declare components that are part of the module. This is important for Angular to know which components are available within the module.
In Angular, the _____ pipe is used to automatically subscribe and unsubscribe from an Observable.
- async
- map
- reduce
- switchMap
In Angular, the async pipe is used to automatically subscribe and unsubscribe from an Observable. It simplifies the management of Observable subscriptions in templates, ensuring proper cleanup.
Custom validators in Angular are functions that return an object of type ____ when the validation fails.
- FormControl
- ValidationErrors
- number
- string
Custom validators in Angular are functions that return an object of type ValidationErrors when the validation fails. The ValidationErrors object holds information about the validation error and can be used to display error messages.
How can you ensure that an Observable completes and releases resources after emitting a certain number of values?
- Use the complete method
- Use the finalize operator
- Use the takeUntil operator
- Use the unsubscribe method
To ensure an Observable completes and releases resources after emitting a certain number of values, you can use the takeUntil operator to specify a condition for completion.
What is the difference between dirty and touched properties of a form control?
- Dirty indicates interaction, touched indicates modification.
- Dirty indicates it's required, touched indicates it's optional.
- Dirty indicates modification, touched indicates interaction.
- Dirty indicates optional, touched indicates required.
In Angular, the dirty property indicates that a form control has been modified, while the touched property indicates that a form control has been interacted with (e.g., focused or blurred).
What would you test in a custom pipe that formats and displays dates?
- Pipe's NgModule
- Pipe's constructor
- Pipe's template
- Pipe's transform method
In a custom date formatting pipe, you should test the Pipe's transform method to ensure it formats and displays dates correctly.
You are testing a custom pipe that transforms user input into a URL-friendly format. What edge cases should you consider in your tests?
- Empty input
- Invalid URL characters
- Long input
- Special characters
When testing the custom pipe, you should consider special characters as an edge case. Special characters may need proper transformation, and testing how the pipe handles them is important.