Angular - Creating Components

Introduction

In Angular, components are the basic building blocks of any application. They are essentially a combination of HTML, CSS, and TypeScript code that defines a part of the UI.

Syntax

To create a new component in Angular, follow the given syntax:

ng generate component component-name

This will create a new folder in the app directory which contains four files:

• component-name.component.ts
• component-name.component.html
• component-name.component.css
• component-name.component.spec.ts

Example

Let's create a new component in an Angular application. Open a terminal window and navigate to the project folder. Run the following command:

ng generate component hello-world

This will create a new folder named hello-world with the four files mentioned above. Now, open the hello-world.component.ts file and update it as follows:

import { Component } from '@angular/core';

@Component({
  selector: 'app-hello-world',
  templateUrl: './hello-world.component.html',
  styleUrls: ['./hello-world.component.css']
})
export class HelloWorldComponent {
  message = 'Hello, world!';
}

Next, open the hello-world.component.html file and update it as follows:

<p>{{ message }}</p>

Finally, open the app.component.html file and add the following line:

<app-hello-world></app-hello-world>

Output

When you run the application, you should see the following:

Hello, world!

Explanation

Firstly, we generated a new component using the Angular CLI. Then, we created a simple component that displays the message, "Hello, world!" in a paragraph element. We added this component to the app.component.html file so that it gets rendered on the screen.

Use

Components can be used to break down an application into smaller, more manageable chunks. They can be used to display data, receive user input, and handle user interactions. In Angular, a component can have its own internal state and can communicate with other components through input and output properties.

Important Points

• A component is a combination of HTML, CSS, and TypeScript code that defines a part of the UI.
• Components can be created using the Angular CLI.
• The @Component decorator is used to define metadata about a component.
• Components can be used to break down an application into smaller parts that are easier to manage.
• Components can communicate with other components through input and output properties.

Summary

Components are an essential part of any Angular application. They are used to break down an application into smaller, more manageable parts. By following the syntax provided above, you can create a new component using the Angular CLI. The component can then be customized to display data, handle user interactions, and communicate with other components.