Svelte has announced the upcoming Runes feature in Svelte 5, which has yet to be released. This feature serves as a way to specify which variables need to be checked for changes in order to render anew. Unlike before, where Svelte automatically tracked the changes in variables and updated the values accordingly, this approach brings Svelte closer to React’s syntax, which requires the declaration of useState or useEffect. However, the Svelte team asserts that this approach is much easier to handle, especially when the application becomes more complex. As the complexity of an app increases, so does the intricacy of tracking variables. The guidance provided by Runes simplifies the process of writing components.
Svelte confirms that existing app code will still function in Svelte 5, and this new feature will be optional for users to utilize.
TLDR: Svelte has introduced the Runes feature in Svelte 5, allowing users to specify the variables that need to be tracked for changes. This simplifies the component writing process, making it easier to handle complex applications. The feature is optional and existing app code will continue to work in Svelte 5.