watch
Watches a reactive source and runs a callback on changes.
Signature
function watch<T>(source: () => T, callback: (value: T) => void): void;
Parameters
source
: A function returning the value to watch.callback
: A function called with the new value when the source changes.
Example
const state = reactive({ count: 0 });
watch(() => state.count, (value) => console.log(value));
state.count = 1; // Logs: 1
state.count = 2; // Logs: 2