react-native-page-flipper/lib/module/hooks/usePrevious.js

Page Flipper

import { useEffect, useRef } from 'react'; // Hook

const usePrevious = value => {
  // The ref object is a generic container whose current property is mutable ...
  // ... and can hold any value, similar to an instance property on a class
  const ref = useRef(); // Store current value in ref

  useEffect(() => {
    ref.current = value;
  }, [value]); // Only re-run if value changes
  // Return previous value (happens before update in useEffect above)

  return ref.current;
};

export default usePrevious;
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