svelte/documentation/docs/03-template-syntax/02-if.md

title: {#if ...}

<!--- copy: false  --->
{#if expression}...{/if}

<!--- copy: false  --->
{#if expression}...{:else if expression}...{/if}

<!--- copy: false  --->
{#if expression}...{:else}...{/if}

Content that is conditionally rendered can be wrapped in an if block.

{#if answer === 42}
	<p>what was the question?</p>
{/if}

Additional conditions can be added with {:else if expression}, optionally ending in an {:else} clause.

{#if porridge.temperature > 100}
	<p>too hot!</p>
{:else if 80 > porridge.temperature}
	<p>too cold!</p>
{:else}
	<p>just right!</p>
{/if}

(Blocks don't have to wrap elements, they can also wrap text within elements.)