In Svelte, variables created during the onMount lifecycle function can be accessed within the component's scope and used in the template or other parts of the component. Here's how you can access variables created during the onMount function:

html
<script> import { onMount } from 'svelte'; let count = 0; onMount(() => { // This code runs once the component is mounted to the DOM console.log('Component mounted'); count = 42; // You can modify the 'count' variable here }); </script> <main> <h1>Hello Svelte!</h1> <p>Count: {count}</p> </main>

In this example, we have a simple Svelte component that declares a count variable with an initial value of 0. Inside the onMount function, we log a message to the console and update the count variable to 42.

The count variable is accessible within the <main> section of the component's template. When the component is mounted, the onMount function is executed, and the value of count is updated to 42. The updated value of count will be reflected in the template, and you'll see "Count: 42" rendered on the page.

Keep in mind that the onMount function is executed once, after the component is mounted to the DOM. If you need to react to changes in props or other reactive values, you can use reactive statements or the $: syntax in Svelte.

Here's an example of using the onMount function to fetch data and update the component state:

html
<script> import { onMount } from 'svelte'; let data = null; onMount(async () => { const response = await fetch('https://api.example.com/data'); data = await response.json(); }); </script> <main> {#if data} <h1>Data Loaded:</h1> <pre>{JSON.stringify(data, null, 2)}</pre> {:else} <p>Loading data...</p> {/if} </main>

In this example, we use the onMount function to fetch data from an API and update the data variable when the data is available. The conditional rendering in the template ensures that we display "Loading data..." while waiting for the API response, and then display the loaded data once it's available.

Have questions or queries?
Get in Touch