useEffectWithPreviousValues

useEffectWithPreviousValues

Function
useEffectWithPreviousValues(callback(preValuesreadonlyunknown[]) => void, dependenciesreadonlyunknown[]): void
Parameters
ParameterTypeNotes
callback
(preValuesreadonlyunknown[]) => void
dependencies
readonlyunknown[]

dependencies must be a non-empty array and the length should not change

example:

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const [count, setCount] = useState(0)
const [opened, setOpened] = useState(false)

useEffectWithPreviousValues((preValues) => {
 const [preCount, preOpened] = preValues

 if (count !== preCount) {
   console.log('count changes')
 }

 if (opened !== preOpened) {
   console.log('opened changes')
 }
}, [count, opened)
Returns 
void

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