callback function in set state code example

Example 1: react callback set staet

setState(  { name: "Michael" },  () => console.log(this.state));// => { name: "Michael" }

Example 2: react functional components setstate callback

const [state, setState] = useState({ name: "Michael" })
const isFirstRender = useRef(true)

useEffect(() => {
  if (!isFirstRender.current) {
    console.log(state) // do something after state has updated
  }
}, [state])

useEffect(() => { 
  isFirstRender.current = false // toggle flag after first render/mounting
}, [])

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Misc Example

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