Getting Started with Svelte: A Beginner's Guide

Svelte is a modern JavaScript framework that takes a unique approach to building user interfaces. Unlike React or Vue, which do most of their work in the browser, Svelte shifts that work to a compile step that happens when you build your app.

What Makes Svelte Different?

Svelte converts your components into highly efficient imperative code that surgically updates the DOM. As a result, you're able to write ambitious applications with excellent performance characteristics.

Here are some key advantages of Svelte:

• No Virtual DOM: Svelte doesn't use a Virtual DOM, which can lead to better performance.
• Less Code: Svelte apps typically require less code than equivalent apps built with other frameworks.
• Truly Reactive: Reactivity is built into the language, not added with APIs like React's useState or Vue's reactive.
• No Runtime Library: The framework doesn't ship to your users, just the compiled code they need.

Setting Up Your First Svelte Project

Getting started with Svelte is straightforward. Here's how to create your first project:

# Create a new project with SvelteKit (recommended)
npm create svelte@latest my-svelte-app

# Navigate to the project directory
cd my-svelte-app

# Install dependencies
npm install

# Start the development server
npm run dev

Creating Your First Component

Svelte components are written in .svelte files, which contain HTML, CSS, and JavaScript. Here's a simple example:

<script>
  let count = 0;
  
  function increment() {
    count += 1;
  }
</script>

<button on:click={increment}>
  Clicked {count} {count === 1 ? 'time' : 'times'}
</button>

<style>
  button {
    font-family: inherit;
    font-size: inherit;
    padding: 1em 2em;
    color: #ff3e00;
    background-color: rgba(255, 62, 0, 0.1);
    border-radius: 2em;
    border: 2px solid rgba(255, 62, 0, 0);
    outline: none;
    width: 200px;
    font-variant-numeric: tabular-nums;
    cursor: pointer;
  }
  
  button:focus {
    border: 2px solid #ff3e00;
  }
  
  button:active {
    background-color: rgba(255, 62, 0, 0.2);
  }
</style>

Reactivity in Svelte

One of Svelte's most powerful features is its built-in reactivity. When you update a variable that a component references, Svelte automatically updates the DOM:

<script>
  let count = 0;
  
  // This will update automatically when count changes
  $: doubled = count * 2;
  
  function increment() {
    count += 1;
  }
</script>

<button on:click={increment}>Count: {count}</button>
<p>Doubled: {doubled}</p>

Conclusion

Svelte offers a refreshing approach to building web applications. Its compiler-based approach results in smaller bundle sizes and better runtime performance, while its intuitive syntax makes it a joy to work with.

If you're looking for a modern framework that prioritizes developer experience without sacrificing performance, Svelte is definitely worth exploring.

For more information, check out the official Svelte documentation and tutorial.