Angular Interview Questions

The Angular CLI (Command Line Interface) is a powerful tool provided by Angular to help developers create, manage, and build Angular applications efficiently. It streamlines many of the development tasks by providing a set of commands that automate various aspects of the development workflow, such as setting up a new project, generating components and services, running the application, and building for production.

Key Features of Angular CLI:

1. Project Initialization:
   • Quickly sets up a new Angular project with a recommended directory structure and configuration.
2. Code Generation:
   • Provides commands to generate boilerplate code for components, services, directives, modules, and more, following best practices.
3. Development Server:
   • Runs a local development server with live reload capabilities, allowing developers to see changes in real-time.
4. Building and Deployment:
   • Facilitates building the application for different environments (development, production) with optimized settings.
5. Testing:
   • Integrates with testing frameworks and provides commands to run unit tests and end-to-end tests.

Common Angular CLI Commands:

1. Creating a New Project:

   • Command: ng new <project-name>
   • Purpose: Initializes a new Angular project with the specified name.
   • Example:

     ng new my-angular-app

2. Serving the Application:

   • Command: ng serve
   • Purpose: Builds and serves the application, and watches for file changes. The default development server runs on http://localhost:4200/.
   • Example:

     ng serve

3. Generating Components:

   • Command: ng generate component <component-name> or ng g c <component-name>
   • Purpose: Generates a new component with the specified name, including the necessary files and boilerplate code.
   • Example:

     ng generate component my-component
     ng g c my-component

4. Generating Services:

   • Command: ng generate service <service-name> or ng g s <service-name>
   • Purpose: Generates a new service with the specified name, including the necessary files and boilerplate code.
   • Example:

     ng generate service my-service
     ng g s my-service

5. Generating Modules:

   • Command: ng generate module <module-name> or ng g m <module-name>
   • Purpose: Generates a new module with the specified name.
   • Example:

     ng generate module my-module
     ng g m my-module

6. Building the Application:

   • Command: ng build
   • Purpose: Compiles the application into an output directory (dist/ by default). Can be configured for different environments.
   • Example:

     ng build
     ng build --prod  # For production build

7. Running Tests:

   • Command: ng test
   • Purpose: Runs unit tests using the configured testing framework (usually Karma and Jasmine).
   • Example:

     ng test

8. Running End-to-End Tests:

   • Command: ng e2e
   • Purpose: Runs end-to-end tests using the configured testing framework (usually Protractor).
   • Example:

     ng e2e

9. Updating Angular and Dependencies:

   • Command: ng update
   • Purpose: Updates Angular CLI, Angular framework, and other dependencies to the latest version.
   • Example:

     ng update @angular/cli @angular/core

10. Linting the Project:

    • Command: ng lint
    • Purpose: Runs linting tools on the project’s code to ensure it follows coding standards.
    • Example:

      ng lint

Example Workflow Using Angular CLI:

1. Create a New Project:

   ng new my-angular-app
   cd my-angular-app

2. Serve the Application:

   ng serve

3. Generate a New Component:

   ng generate component user-profile

4. Generate a New Service:

   ng generate service user

5. Build the Application for Production:

   ng build --prod

6. Run Unit Tests:

   ng test

In Summary:

The Angular CLI is an essential tool for Angular developers, providing commands that simplify the setup, development, testing, and deployment of Angular applications. By automating many common tasks and following best practices, the Angular CLI helps developers be more productive and ensures consistency across Angular projects.