{@const ...}

{@const ...} 标签定义了一个本地常量。

¥The {@const ...} tag defines a local constant.

{#each boxes as box}
	{@const area = box.width * box.height}
	{box.width} * {box.height} = {area}
{/each}

{@const} 仅允许作为块（{#if ...}、{#each ...}、{#snippet ...} 等）的直接子块（<Component /> 或 <svelte:boundary>）。

¥{@const} is only allowed as an immediate child of a block — {#if ...}, {#each ...}, {#snippet ...} and so on — a <Component /> or a <svelte:boundary>.