Svelte · Senior · Question 1 of 75

What model does Svelte 5 reactivity use under the hood?

✓Correct answer: Signals: reading state inside an effect or derived registers a dependency, writing it schedules only the affected effects
2Dirty checking of the whole component after each event
3Virtual DOM diffing

Explanation

Template expressions are effects too. Runes are the syntax over this runtime; Svelte 4 instead relied on the compiler instrumenting assignments.

Further reading

Test yourself

Take the Svelte · Senior quiz: questions and options are shuffled, and you get a review of your mistakes at the end.