usage

import React, { useEffect, useState } from "react";
import ReactDom from "react-dom";

const useProduct = (productName) => {

  const [proList, setProList] = useState([]);

  useEffect(() => {

    setTimeout(() => {
      setProList([1, 2, 3]);
    }, 1000);
    
  }, []);

  return proList;
  
}

const Index = () => {

  const proList = useProduct();

  return <>
    {proList.length}
  </>;

}

ReactDom.render(<Index />, document.getElementById("root"));