Useful things

useful-things.jsx

const Something = useMemo(() => {
    const dictionary = {};

    currentItems.forEach((item) => {
      const categoryName = item.categoryName;
      if (dictionary[categoryName]) {
        // push item in a list
        dictionary[categoryName].push(item);
      } else {
        // create a list with an item;
        dictionary[categoryName] = [item];
      }
    });
    return dictionary;
  });