svelte/documentation/tutorial/04-logic/01-if-blocks/app-a/App.svelte

<script>
	let user = { loggedIn: false };

	function toggle() {
		user.loggedIn = !user.loggedIn;
	}
</script>

<button on:click={toggle}> Log out </button>

<button on:click={toggle}> Log in </button>