react, useEffect: Can you use global variable as a dependent variable?

Question

window.data = {}

useEffect(() => {
// do something
}, [window.data])

Does the above code makes sense?

since window.data is global, it won't be different on renders, and the effect won't execute?

Answer 1

No, that won't work. Effect could only be triggered when component is rerendered and dependencies change. Changing global variables won't cause a rerender, so the effect won't run.