useEffect() comes in very handy if you need to trigger an action or “side effect” from an object modification.
In the example below we have an array of names
const names = ["Alex", "Bob", "Sally"]
If we want to save the names array to localStorage every time it is modified we can implement useEffect()
import { useEffect } from "react"
function App() {
// other setup code...
useEffect(() => {
localStorage.setItem("notes", JSON.stringify(names))
},[names])
// [names] is known as a dependency array, on every `names` change
// `useEffect` will get executed
// component rendering code.....
}
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