svelte/documentation/examples/06-lifecycle/01-ondestroy/App.svelte

<script>
	import { onInterval } from './utils.js';

	let seconds = 0;
	onInterval(() => (seconds += 1), 1000);
</script>

<p>
	The page has been open for
	{seconds}
	{seconds === 1 ? 'second' : 'seconds'}
</p>