Answer: Angular is a TypeScript-based open-source web application framework developed by Google. It is a complete rewrite of AngularJS, designed to address the shortcomings and provide a more modern and efficient framework for building web applications.
Answer: Two-way data binding is a feature in Angular that allows automatic synchronization of data between the model and the view. Changes in the model update the view, and vice versa, without the need for explicit code to update the DOM or the model.
Answer: Angular CLI (Command Line Interface) is a powerful tool for initializing, developing, testing, and deploying Angular applications. It provides commands to generate components, services, modules, and more, simplifying the development process and ensuring best practices are followed.
Answer: Decorators are a design pattern in Angular used to attach metadata to classes, functions, or properties. They are often used to define and configure Angular components, services, and modules, influencing their behavior and relationships.
Answer: Dependency Injection (DI) in Angular is a design pattern where a class receives its dependencies from an external source rather than creating them itself. It promotes modular and testable code by making components more reusable and easier to maintain.
Answer: An Angular module is a logical container for organizing and managing related components, directives, pipes, and services in an Angular application. It helps in structuring the application, promoting reusability, and facilitating lazy loading for better performance.
Answer: Directives in Angular are markers on a DOM element that tell Angular to do something with that element. Examples of built-in directives include ngIf, ngFor, ngSwitch, and ngClass, which are used for conditional rendering, iteration, switching, and class manipulation, respectively.
Answer: Angular services are singleton objects that are used to encapsulate and share logic or data across multiple components. They are commonly used for tasks such as data fetching, business logic, and communication between components. Services promote code reusability and maintainability.
Answer: Angular routing is a mechanism that allows navigation between different components or views in a single-page application. It is achieved by configuring routes, which map URL paths to specific components. Angular's router helps in managing navigation and providing a seamless user experience.
Answer: Pipes in Angular are used to transform and format data in the template. Examples of built-in pipes include the DatePipe for formatting dates, the CurrencyPipe for formatting currency, and the UpperCasePipe for transforming text to uppercase. Pipes are a way to enhance the presentation of data in the user interface.
Answer: Angular interpolation is a way to bind expressions directly into the HTML template. It uses double curly braces {{ expression }}. Property binding, on the other hand, is a one-way data binding method that binds a property of a DOM element to a field in the component.
Answer: Angular guards are used to control the navigation flow in an Angular application. Examples include canActivate, canDeactivate, canActivateChild, and canLoad. They allow developers to implement logic to determine whether a route can be activated, deactivated, or loaded.
Answer: Angular ng-content is a mechanism for passing content into a component from the outside. It allows the insertion of external content into specific places within a component's template, providing flexibility and reusability in component design.
Answer: ngOnChanges is a lifecycle hook in Angular that is called when the input properties of a component change. ngOnInit is another lifecycle hook that is called once after the component is initialized. ngOnChanges is triggered whenever input properties change, while ngOnInit runs once during component initialization.
Answer: Angular Ivy is the next-generation rendering engine for Angular. It improves performance by enabling smaller bundle sizes, faster compilation, and better runtime performance. It also introduces features like improved debugging and enhanced template type checking.
Answer: Angular forms are a way to handle user input and validation in applications. Template-driven forms are based on directives in the template, and Angular automatically creates and manages the form controls. Reactive forms are built programmatically using form control objects, providing more flexibility and control over form behavior.
Answer: Angular services are used to organize and share code across components. The @Injectable decorator's providedIn property is used to specify the root injector for a service. When providedIn is set to 'root', the service is a singleton available throughout the application. If set to a specific module, it is available only within that module.
Answer: Reactive programming in Angular involves using RxJS (Reactive Extensions for JavaScript) to handle asynchronous tasks and events. It provides observable sequences and operators for composing and transforming data. RxJS is widely used in Angular for handling HTTP requests, event handling, and managing state in a reactive manner.
Answer: Angular directives are markers on a DOM element that tell Angular to do something with that element. Structural directives, such as *ngIf and *ngFor, modify the structure of the DOM by adding or removing elements. Attribute directives, like ngClass and ngStyle, change the appearance or behavior of an element.
Answer: Angular testing involves the verification of the behavior and functionality of Angular applications. Angular provides tools like TestBed for configuring and creating the testing module, and Jasmine for writing unit tests. Protractor is used for end-to-end (E2E) testing of Angular applications.
Answer: Angular ngZone is a service that provides a zone context for executing asynchronous tasks. It is crucial for change detection in Angular because it allows the framework to be aware of asynchronous operations and ensures that the associated change detection cycle is triggered appropriately.
Answer: Angular change detection is a mechanism that automatically updates the view to reflect the current state of the application. It works by checking for changes in the component's state and updating the DOM accordingly. Angular uses zones to intercept asynchronous operations and trigger change detection when needed.
Answer: @ViewChild and @ContentChild are decorators used in Angular to query and access child components or elements. @ViewChild is used to query a component or directive from the component's view, while @ContentChild is used to query a component or directive that is projected into the component's content.
Answer: ngIf else is a directive in Angular used for conditional rendering. It allows you to conditionally display content based on a true or false condition. ngSwitch is another directive that is used for more complex conditional rendering, providing a way to switch between multiple cases based on a value.
Answer: Angular Ahead-of-Time (AOT) compilation is a process where the Angular application is compiled at build time rather than at runtime. This results in smaller bundle sizes, faster rendering, and better runtime performance compared to Just-in-Time (JIT) compilation, where compilation occurs in the browser at runtime.
Answer: Angular lazy loading is a technique where modules are loaded on-demand rather than being loaded with the initial application bundle. This helps in reducing the initial loading time of the application, as only the required modules are loaded when the user navigates to a specific route, improving overall performance.
Answer: Angular best practices for performance include using AOT compilation, lazy loading modules, optimizing change detection, minimizing the use of ngFor and ngIf in templates, leveraging trackBy for ngFor, using OnPush change detection strategy, and optimizing the size of bundles through code splitting.
Answer: Angular decorators are a way to extend and modify the behavior of classes, methods, or properties. Examples of custom decorators in Angular include @Input and @Output for component communication, and @HostListener for handling DOM events. Custom decorators allow developers to add metadata and behavior to components.
Answer: Angular HttpClient is a service for making HTTP requests in Angular applications. It provides a high-level API for sending and receiving data from a server. HttpClient is commonly used for tasks such as fetching data from a backend API and handling CRUD operations in Angular applications.
Answer: Angular ngModule is a mechanism for organizing and structuring an Angular application. It is used to consolidate components, directives, pipes, and services into cohesive units. ngModule helps in managing dependencies, defining entry components, and configuring providers, contributing to the overall organization and modularity of the application.
Answer: Angular ngClass is a directive used for dynamically adding or removing CSS classes based on conditions in Angular templates. It allows for flexible and conditional styling of elements, making it easier to manage the appearance of components based on component state or other conditions.
Answer: Angular ngZone is a service that provides a zone context for executing asynchronous tasks. It is crucial for performance optimization as it helps Angular to be aware of asynchronous operations and manage change detection more efficiently. ngZone ensures that change detection is triggered only when necessary, reducing unnecessary updates and improving overall performance.
Answer: providedIn in the @Injectable decorator is used to specify the injector scope for a service. When providedIn is set to 'root', the service becomes a singleton shared throughout the application. If set to a specific module, the service is available only within that module. This impacts the application by influencing how instances of the service are created and managed.
Answer: Angular ngModel is a directive used for two-way data binding in forms. It binds the value of an input element to a property in the component, allowing changes in the input to update the component property, and vice versa. ngModel is commonly used in form controls to facilitate bidirectional data flow between the template and the component.
Answer: Angular interceptors are a feature that allows developers to intercept and modify HTTP requests and responses globally. They are useful for tasks such as adding headers, handling errors, or logging information. Interceptors are configured in the Angular HttpClientModule and provide a way to apply common behavior across multiple HTTP requests.
Answer: Angular ngContentOutlet is a directive used for dynamic content projection. It allows the dynamic insertion of content into a designated location within a component's template. ngContentOutlet is particularly useful when the content to be projected is not known at compile time, providing flexibility in component composition and content rendering.
Answer: Angular ngOnInit is a lifecycle hook that is called after the component has been initialized and before the first change detection cycle. It is commonly used to perform initialization tasks, such as fetching initial data or setting up subscriptions. ngOnInit is a good place to put code that needs to run once when the component is created.
Answer: Angular ViewEncapsulation is a mechanism that encapsulates the styles of a component to prevent them from affecting other components. It uses shadow DOM or emulated shadow DOM to scope styles to the component's view. ViewEncapsulation ensures that styles defined in one component do not leak into other components, promoting component isolation and reusability.
Answer: Angular ngRx is a state management library inspired by Redux. It provides a predictable state container for managing the state of an Angular application in a centralized and immutable way. ngRx helps in managing complex application state, making it easier to debug, test, and maintain large Angular applications.
Answer: Angular contentChild and contentChildren decorators are used to query and access content projected into a component. contentChild is used to query a single projected component or directive, while contentChildren is used to query multiple projected components or directives. These decorators provide a way to interact with and manipulate the content projected into a component.
Answer: Angular ngZone is a service that provides a zone context for executing asynchronous tasks. It impacts change detection by allowing Angular to track asynchronous operations. When operations occur outside the Angular zone, change detection is triggered, ensuring that the view reflects the most up-to-date state of the application.
Answer: Angular ElementRef is a wrapper around a native element, providing access to the underlying DOM element in Angular components. Renderer2 is a service that provides methods for interacting with the DOM in a way that is agnostic to the rendering platform. They are used to manipulate the DOM safely in Angular applications.
Answer: Angular ngOnInit is a lifecycle hook that is called after Angular has initialized a component's properties. It is used for initialization tasks, such as fetching data from a service or setting up subscriptions. ngOnInit is a good place to perform actions that need to happen once when the component is created.
Answer: Angular ng-template is a directive used to declare a template block that can be reused. ng-container is a structural directive that does not create any DOM elements. Together, they are often used to create reusable templates that are not rendered directly in the DOM but can be instantiated and displayed as needed.
Answer: Angular ViewChild is a decorator used to query and interact with a child component or directive from its parent component. It allows the parent component to access properties and methods of the child component, facilitating communication and coordination between parent and child components.
Answer: Angular ng-container is a structural directive used to group elements in the template without adding an extra element to the DOM. It is often used to apply structural directives like *ngIf or *ngFor to a block of elements without introducing an additional wrapper element in the rendered output.
Answer: Angular ngRx is a state management library for Angular applications based on the principles of Redux. It provides a centralized store for managing application state in a predictable and immutable way. ngRx facilitates the management of complex state, making it easier to debug, test, and maintain large-scale Angular applications.
Answer: Angular directive's lifecycle hooks are methods that allow developers to tap into the lifecycle of a directive and perform actions at specific points. Examples of common hooks include ngOnChanges, ngOnInit, ngDoCheck, ngOnDestroy, and more. These hooks provide opportunities to perform tasks such as initialization, change detection, and cleanup.
Answer: Angular ngModel is a directive used for two-way data binding in forms. It binds the value of an input element to a property in the component, allowing changes in the input to update the component property, and vice versa. ngModel is commonly used to facilitate bidirectional data flow between the template and the component in form controls.
Answer: Angular pipes are used for transforming and formatting data in the template. Examples of built-in pipes include DatePipe for formatting dates, CurrencyPipe for formatting currency, and UppercasePipe for transforming text to uppercase. Pipes enhance the presentation of data in the user interface and can be customized or extended for specific use cases.
Answer: Angular ngZone is a service that provides a zone context for executing asynchronous tasks. It impacts change detection by allowing Angular to track asynchronous operations. When operations occur outside the Angular zone, change detection is triggered, ensuring that the view reflects the most up-to-date state of the application.
Answer: Angular ElementRef is a wrapper around a native element, providing access to the underlying DOM element in Angular components. Renderer2 is a service that provides methods for interacting with the DOM in a way that is agnostic to the rendering platform. They are used to manipulate the DOM safely in Angular applications.
Answer: Angular ngOnInit is a lifecycle hook that is called after Angular has initialized a component's properties. It is used for initialization tasks, such as fetching data from a service or setting up subscriptions. ngOnInit is a good place to perform actions that need to happen once when the component is created.
Answer: Angular ng-template is a directive used to declare a template block that can be reused. ng-container is a structural directive that does not create any DOM elements. Together, they are often used to create reusable templates that are not rendered directly in the DOM but can be instantiated and displayed as needed.
Answer: Angular ViewChild is a decorator used to query and interact with a child component or directive from its parent component. It allows the parent component to access properties and methods of the child component, facilitating communication and coordination between parent and child components.
Answer: Angular ng-container is a structural directive used to group elements in the template without adding an extra element to the DOM. It is often used to apply structural directives like *ngIf or *ngFor to a block of elements without introducing an additional wrapper element in the rendered output.
Answer: Angular ngRx is a state management library for Angular applications based on the principles of Redux. It provides a centralized store for managing application state in a predictable and immutable way. ngRx facilitates the management of complex state, making it easier to debug, test, and maintain large-scale Angular applications.
Answer: Angular directive's lifecycle hooks are methods that allow developers to tap into the lifecycle of a directive and perform actions at specific points. Examples of common hooks include ngOnChanges, ngOnInit, ngDoCheck, ngOnDestroy, and more. These hooks provide opportunities to perform tasks such as initialization, change detection, and cleanup.
Answer: Angular ngModel is a directive used for two-way data binding in forms. It binds the value of an input element to a property in the component, allowing changes in the input to update the component property, and vice versa. ngModel is commonly used to facilitate bidirectional data flow between the template and the component in form controls.
Answer: Angular pipes are used for transforming and formatting data in the template. Examples of built-in pipes include DatePipe for formatting dates, CurrencyPipe for formatting currency, and UppercasePipe for transforming text to uppercase. Pipes enhance the presentation of data in the user interface and can be customized or extended for specific use cases.
Answer: Angular dependency injection is a design pattern where components and services are given their dependencies rather than creating them directly. This promotes modularity, reusability, and easier testing by making components and services more flexible and decoupled from their dependencies.
Answer: Angular ngContent is a directive used for content projection, allowing the insertion of content into a component's template from the outside. ngContentSelect is used to conditionally select projected content based on a provided selector. These directives provide flexibility in composing and styling components.
Answer: Angular directives are markers on a DOM element that tell Angular to do something with that element. Directives include structural directives like *ngIf and *ngFor, and attribute directives like ngStyle and ngClass. Components are a type of directive with templates, while directives are generally used to add behavior to existing elements.
Answer: Angular ngRx store is a state management library that follows the principles of Redux. It provides a single source of truth for the application state and enables predictable state changes through actions and reducers. The store facilitates the management of complex application state in a scalable and maintainable way.
Answer: Angular dynamic component loading involves loading components dynamically at runtime. This is useful when the components needed are not known at compile time, such as in scenarios where components are determined by user actions or external configuration. Dynamic loading enhances flexibility and reduces initial bundle size.
Answer: Angular ngStyle is a directive that allows dynamic styling of elements based on property values in the component. ngClass is a directive that dynamically adds or removes CSS classes based on conditions. Both directives provide a way to conditionally style elements in response to changes in the component state.
Answer: Angular ngOnInit is a lifecycle hook that is called after Angular has initialized a component's properties. It is considered part of the component lifecycle because it provides a specific point in the component's lifecycle where initialization tasks can be performed, ensuring that the component is ready for use.
Answer: Angular ngZone is a service that provides a zone context for executing asynchronous tasks. It helps manage asynchronous operations by allowing Angular to be aware of these tasks. NgZone triggers change detection when asynchronous operations complete, ensuring that the view is updated appropriately.
Answer: Angular directives are instructions in the DOM that Angular uses to extend the functionality of HTML elements. They are markers on a DOM element that tell Angular to do something with that element. Directives can be used to add behavior, manipulate the DOM, or create reusable components within an Angular application.
Answer: Angular reactive forms and template-driven forms are two approaches for handling forms in Angular. Reactive forms are model-driven and created programmatically, offering more control and flexibility. Template-driven forms are created using directives in the template, making them easier to set up but with less control than reactive forms.
Answer: Angular Universal is a technology that enables server-side rendering (SSR) for Angular applications. SSR improves initial page load performance by rendering Angular components on the server and sending pre-rendered HTML to the client, reducing client-side processing.
Answer: Angular Ivy is the latest rendering engine in Angular. It enhances performance by generating smaller and more efficient JavaScript bundles, improving compilation speed, enabling better tree-shaking, and providing improved debugging and runtime performance.
Answer: Angular Elements is a feature that allows the creation of Angular components as custom elements (Web Components). This facilitates the usage of Angular components in non-Angular environments and frameworks, making them reusable across different projects and technologies.
Answer: Angular Schematics is a workflow tool that automates the creation, modification, and maintenance of Angular projects. It streamlines project development by providing a way to generate boilerplate code, add components, modules, services, and perform other common tasks, improving consistency across projects.
Answer: ChangeDetectionStrategy.OnPush is a change detection strategy in Angular that makes the framework check for changes only when the component's inputs change or when an event is triggered. It's useful for optimizing performance in components where the data doesn't change frequently, reducing unnecessary checks.
Answer: Angular ngUpgrade is a library that helps in the gradual migration of AngularJS (Angular 1.x) applications to Angular. It allows both frameworks to run simultaneously, enabling developers to upgrade components and services incrementally rather than requiring a complete rewrite of the application.
Answer: Angular Zone.js is a library that helps Angular manage asynchronous tasks and events. It provides a zone context for execution, allowing Angular to track asynchronous operations and trigger change detection when needed. Zone.js is fundamental to Angular's change detection mechanism.
Answer: Angular AOT compilation is a build process that compiles Angular applications at build time rather than at runtime. It results in smaller bundle sizes, faster rendering, and improved security. JIT compilation, on the other hand, compiles the application in the browser at runtime.
Answer: Angular Zone-less change detection involves running change detection outside the Angular zone. This can be useful in scenarios where you want to optimize performance by reducing the frequency of change detection checks or when integrating with third-party libraries that don't play well with zones.
Answer: Angular Microfrontends is an architectural pattern that involves breaking a large Angular application into smaller, independently deployable micro-applications. Each micro-app serves as a standalone Angular application, allowing teams to work on and deploy components independently, promoting modularity and scalability.
Answer: Angular i18n is a feature that supports internationalization (i18n) in Angular applications. It allows developers to create multilingual applications by providing tools for translating text and formatting dates, numbers, and currencies based on the user's locale.
Answer: In Angular ngModule, providers are used to configure the dependency injection system. They define how instances of services are created and injected throughout the application. Understanding ngModule providers is crucial for controlling the scope and lifecycle of services in Angular applications.
Answer: Angular Dynamic Component Loader allows the dynamic creation and loading of components at runtime. This is useful when the components needed are determined dynamically, enabling scenarios such as dynamic forms, dialogs, or components loaded based on user interactions or external configurations.
Answer: Angular TestBed is a utility in Angular for configuring and creating instances of Angular testing modules. It is a key tool for testing Angular components, services, and other units of code. TestBed provides methods to configure dependencies, mock services, and create instances for testing purposes.
Answer: Angular Ivy's Differential Loading is a feature that optimizes the delivery of JavaScript bundles by generating separate bundles for modern and legacy browsers. Modern browsers receive a smaller, more efficient bundle, while legacy browsers receive a larger bundle with additional polyfills, ensuring optimal performance for each browser type.