AI solution for React Coding Question on BFE.dev
16. useUpdateEffect()

To implement the useUpdateEffect() custom hook, you can utilize the useEffect() hook along with the useRef() hook to track the initial render.

Here's a possible implementation:

import { useEffect, useRef } from 'react';

const useUpdateEffect = (callback, dependencies) => {
  const isFirstRender = useRef(true);

  useEffect(() => {
    if (isFirstRender.current) {
      isFirstRender.current = false;
      return;
    }

    return callback();
  }, dependencies);
};

export default useUpdateEffect;

In this implementation, we use the isFirstRender variable, which is a mutable ref object created using the useRef() hook. The ref object retains its value across re-renders, and we set its initial value to true.

We then use the useEffect() hook to execute the callback only after the initial render. We achieve this by checking the value of isFirstRender.current before executing the callback. If it is true, we set it to false and return early from the effect without calling the callback. On subsequent renders, the value of isFirstRender.current will be false, allowing us to run the callback normally.

Remember that the useEffect() hook has a dependency array as its second argument, which determines when the effect should be re-evaluated. This dependency array is passed to the useUpdateEffect() hook as the dependencies parameter, allowing us to control when the callback should be triggered.