Sveltejs Academy · Lesson

{#if} {#else if} {#else}

Conditionally render markup based on JavaScript expressions.

Lesson 1 of 413 steps

{#if} {#else if} {#else} is a free Sveltejs Academy lesson on CoddyKit. This is lesson 1 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Sveltejs Academy learning path, and your progress syncs across the web and the CoddyKit app. The Sveltejs Academy course includes 4 lessons in total.

Conditional Blocks

Svelte conditionals look like Handlebars: {#if}, {:else if}, {:else}, closed with {/if}.

Basic Example

Show one branch or another based on a boolean expression.

{#if loggedIn}
  <p>Welcome back!</p>
{:else}
  <p>Please sign in.</p>
{/if}

Multiple Branches

Chain with {:else if} for multiple conditions.

{#if score > 90}
  <p>A</p>
{:else if score > 75}
  <p>B</p>
{:else}
  <p>C</p>
{/if}

Expressions Are JavaScript

The condition can be any valid JavaScript expression.

{#if items.length > 0 && !isLoading}

Closing Tag

Always close with {/if}. Missing closes are compile errors.

Nested if

Conditionals nest freely inside other Svelte blocks and HTML.

{#if user}
  {#if user.admin}
    <Admin />
  {/if}
{/if}

No Switch

Svelte has no built-in switch block. Use chained {:else if} or compute a variable.

Combining with each

You can wrap a list in a conditional to render only when items exist.

{#if items.length}
  {#each items as item}<li>{item}</li>{/each}
{/if}

Reactivity Inside

The condition is reactive: whenever its dependencies change, Svelte re-evaluates and swaps branches.

Animations on if

You can attach transition: directives to elements inside if blocks to animate entry and exit.

Empty Branches

You may have an if block with no else. The else is optional.

Quick Check

How is a Svelte if block closed?

Answer it in the interactive lesson

Recap

Use {#if}/{:else if}/{:else}/{/if} for conditional rendering. The expression is plain JS.

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Frequently Asked Questions

Is the “{#if} {#else if} {#else}” lesson free?

Yes — the full text of “{#if} {#else if} {#else}” is free to read here on the web. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Sveltejs Academy course, upgrade to CoddyKit PRO. The Sveltejs Academy course includes 4 lessons in total.

What will I learn in “{#if} {#else if} {#else}”?

Conditionally render markup based on JavaScript expressions. You practise Sveltejs Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.

Do I need any experience to start Sveltejs Academy?

No prior experience is required. Sveltejs Academy on CoddyKit is structured for beginners through advanced learners, so you can start here or from the beginning and move at your own pace. This is lesson 1 of 4.

How long does the “{#if} {#else if} {#else}” lesson take?

Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.

Can I write and run code in this Sveltejs Academy lesson?

Yes. Every Sveltejs Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.

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