Which property of a FormControl instance would you check to determine if the user has interacted with a particular form control?
- dirty
- pristine
- touched
- untouched
To determine if the user has interacted with a particular form control in Angular Reactive Forms, you would check the touched property of the FormControl instance. It becomes true when the user has focused and blurred the form control, indicating interaction. The dirty property indicates if the value has changed.
How can you set default headers for every request made by HttpClient in your application?
- By adding headers to each HttpClient request manually
- By configuring HttpHeaders globally
- By modifying the HttpClient constructor
- By using an interceptor
You can set default headers for all HttpClient requests by using an interceptor. Interceptors allow you to intercept outgoing requests and modify them, including adding default headers, before they are sent.
To mock a service in Angular tests, you often replace the real service with a ______ service.
- Mock
- Spy
- Stub
- TestBed
In Angular testing, you typically replace the real service with a "Spy" service. A spy allows you to track calls to service methods, set up return values, and perform other testing-related tasks while avoiding actual service execution.
Which tag is used for multi-slot content projection in Angular?
The tag used for multi-slot content projection in Angular is . It allows you to project content into named slots within a component's template, providing a way to customize the rendering of components from their parent components. is used for defining templates, while and are not standard Angular tags for this purpose.
You have a requirement to build a complex multi-step form with the ability to navigate between steps and validate each step individually. What approach would you take in Angular to handle this?
- Creating separate components for each form step
- Implementing a custom form control for each step
- Using a single large form with form groups
- Utilizing the ngSwitch directive for step navigation
To build a complex multi-step form with navigation and individual step validation, it's advisable to create separate components for each form step in Angular. This approach promotes code modularity, makes step validation and navigation easier, and improves maintainability. Using a single large form with form groups can become unwieldy, and implementing custom form controls for each step might be overcomplicated. The ngSwitch directive is more for conditionally rendering content than for step navigation.
Which property in the Angular routes configuration is used to define lazy-loaded modules?
- component
- loadChildren
- pathMatch
- redirectTo
To define lazy-loaded modules in Angular routes, you use the loadChildren property in the route configuration. This property specifies the path to the module file that should be loaded lazily when the route is activated.
In state management, to listen to changes in a specific slice of the state tree, you'd use ________.
- Actions
- Middleware
- Reducers
- Selectors
In state management libraries like NgRx or Redux, Selectors are used to listen to changes in a specific slice of the state tree. Selectors allow you to extract and compute derived pieces of state efficiently. They are particularly helpful when you need to extract specific data from your state for presentation purposes or when a component should respond to changes in a specific part of the application state.
For projecting content into multiple designated spots within a component's template, you'd use multiple ______ tags with select attributes.
To project content into multiple designated spots within a component's template in Angular, you would use multiple tags with select attributes. The select attribute allows you to specify which projected content should go where based on the content's tag or CSS class. and serve different purposes, and is not a valid Angular element.
The ControlValueAccessor interface provides a bridge between Angular's form controls and a native element in the DOM. This bridge includes methods like writeValue, registerOnChange, and ________.
- setControl
- setFormValue
- setNativeValue
- setValue
The ControlValueAccessor interface in Angular includes methods like writeValue, registerOnChange, and setControl. These methods are essential for synchronizing the value of the form control with the native element in the DOM, making it a crucial interface for custom form control development.
What is the primary purpose of the ControlValueAccessor interface in Angular?
- To control the value of input fields.
- To facilitate communication between a custom form control and a form group.
- To manage Angular component lifecycles.
- To validate form data.
The primary purpose of the ControlValueAccessor interface in Angular is to facilitate communication between a custom form control and a form group. It enables the custom form control to integrate seamlessly with Angular's forms module, allowing the form group to manage its value and validation. This interface is essential when creating custom form controls.