What allows you to dynamically load and render components in Angular?
- Angular dynamic component loader.
- Angular modules.
- Angular services.
- Angular templates.
To dynamically load and render components in Angular, you can use Angular's dynamic component loader. This feature allows you to programmatically load and render components at runtime. Angular templates and modules are part of the Angular framework but don't directly enable dynamic component loading. Angular services provide functionality but aren't specifically for dynamic component loading.
Which providedIn value ensures that a service instance is shared across the entire application?
- 'app'
- 'global'
- 'root'
- 'shared'
The 'root' providedIn value ensures that a service instance is shared across the entire Angular application. When a service is provided with 'root', it becomes a singleton service, and there is only one instance of it created and shared throughout the entire application. This is commonly used for services that should have a single, shared state across components.
What is the primary purpose of the ng serve command in the Angular CLI?
- To build the production-ready application
- To deploy the application
- To run a development server
- To test Angular components
The ng serve command in Angular CLI is primarily used to run a development server. This server serves your Angular application, provides hot module reloading for rapid development, and enables you to view changes in real-time as you code.
When you want to disable a form control conditionally based on some logic, you would use the ______ attribute.
- [conditionalControlDisable]
- [controlToggle]
- [disable]
- [ngControlDisabled]
When you want to disable a form control conditionally based on some logic in Angular template-driven forms, you would use the [disable] attribute. This attribute allows you to bind a condition to the disabled state of a form control, making it either enabled or disabled based on the provided logic. It's a crucial feature for creating dynamic and responsive forms.
For a form control in reactive forms, the property that holds the latest validation errors is called ______.
- validationErrors
- validationStatus
- errors
- validators
In reactive forms, the property that holds the latest validation errors for a form control is called "errors." You can access this property to check for validation errors on a specific form control. It provides information about validation failures, if any. The other options are not the correct property names for holding validation errors in reactive forms.
You're building a layout component that should allow users to inject custom content for the header, sidebar, and main content area. What approach would you take to enable this functionality in the layout component?
- Use ng-template with ng-container to define placeholders for header, sidebar, and main content.
- Use Angular Directives to inject content into the layout component.
- Use Angular Dynamic Components to create header, sidebar, and main content dynamically.
- Use Angular Pipes to transform content for the header, sidebar, and main content areas.
To enable users to inject custom content for the header, sidebar, and main content area in an Angular layout component, you can use ng-templates with ng-containers to define placeholders. Users can then fill these placeholders with their custom content. This approach provides flexibility and is a common pattern for creating layouts with dynamic content. While other options like directives, dynamic components, and pipes have their use cases, they are not the most suitable choice for this specific scenario.
You are building a dynamic form where users can add or remove input fields. Which feature or approach in Angular would be best suited for this requirement?
- FormArray
- Reactive Forms
- Template-driven Forms
- ngFor Directive
To allow users to add or remove input fields dynamically, you would typically use the FormArray feature in Angular. FormArray allows you to create arrays of form controls dynamically, making it ideal for scenarios where the number of input fields can change. Reactive Forms provide a more robust way to manage form data compared to Template-driven Forms, and ngFor is a directive used for rendering lists but doesn't handle form controls.
In template-driven forms, the ______ directive is used to bind an input field to a property in the component's class.
- ngBinding
- ngDirective
- ngModel
- ngTemplate
In template-driven forms in Angular, the "ngModel" directive is used to bind an input field to a property in the component's class. This directive establishes two-way data binding between the form control and the component class property, allowing changes in the input field to be reflected in the component and vice versa.
How can you programmatically navigate to a different route in an Angular application?
- Use the 'navigate' method from the 'Router' service.
- Use the 'navigateTo' function from the 'RouterModule'.
- Use the 'routeTo' function in the component constructor.
- Use the 'routerLink' directive in the HTML template.
To programmatically navigate to a different route in an Angular application, you should use the 'navigate' method from the 'Router' service. This method allows you to navigate to a specified route by providing the route path or an array of route segments. It's a common approach for handling navigation within Angular components or services.
If a parent component needs to send data to a child component, which property decorator should be used?
- @ViewChild
- @Input
- @Output
- @ContentChild
To send data from a parent component to a child component in Angular, you should use the @Input property decorator. It allows the parent component to bind data to a property of the child component. The other options, such as @ViewChild, @Output, and @ContentChild, serve different purposes, like accessing child elements or emitting events.