Introduction

Svelte is a radical new approach to building user interfaces. Whereas traditional frameworks like React and Vue do the bulk of their work in the browser, Svelte shifts that work into a compile step that happens when you build your app. This results in highly efficient code that surgically updates the DOM, leading to a smoother user experience.

Svelte Components

A Svelte application is composed of components. A component could be as simple as a button, as complex as a date picker, or anything in between. A component is a reusable self-contained block of code that encapsulates HTML, CSS, and JavaScript that belong together, packaged in a way that is easy to share and distribute.

Each Svelte component is encapsulated in a .svelte file. The file contains all the markup, logic and styling that the component needs. This approach makes it easier to understand the structure of the component and promotes code reusability and maintainability.

Here's an example of a simple Svelte component:

<script>
  let name = 'world';
</script>

<h1>Hello {name}!</h1>

In this example, the <script> tag contains the component’s state (a single name variable), and the <h1> tag is the component’s markup, which can access the state.

Components can be nested and reused, promoting code reusability and separation of concerns. For example, you might have a Button.svelte component that you use across your application.

Svelte Props

Props (short for properties) are a way of passing data from parent components to child components. In Svelte, you pass props using attributes in the markup.

For example, if you have a Greeting.svelte component that accepts a name prop, you could use it like this:

<script>
  import Greeting from './Greeting.svelte';
</script>

<Greeting name="world" />

And in Greeting.svelte, you would declare the name prop like this:

<script>
  export let name;
</script>

<h1>Hello {name}!</h1>

The export keyword makes name a prop that can be passed in from the parent component.

Conclusion

Svelte components and props are fundamental concepts in Svelte. Components allow you to organize your code into reusable, self-contained blocks, and props allow you to pass data between components. By understanding these concepts, you’ll be well on your way to mastering Svelte.

This is a brief overview and there’s much more to learn about Svelte, including handling user interactions with event listeners, managing application states with stores, and transitioning between component states with animations. Happy coding!