ahooks/es/usePrevious/index.js

react hooks library

import { useRef } from 'react';
var defaultShouldUpdate = function (a, b) {
  return !Object.is(a, b);
};
function usePrevious(state, shouldUpdate) {
  if (shouldUpdate === void 0) {
    shouldUpdate = defaultShouldUpdate;
  }
  var prevRef = useRef();
  var curRef = useRef();
  if (shouldUpdate(curRef.current, state)) {
    prevRef.current = curRef.current;
    curRef.current = state;
  }
  return prevRef.current;
}
export default usePrevious;