initialFunction.ts

// Define a book type
type Book = {
  title: string;
  genre: string;
  publicationYear: number;
};

// Define a list of types
const listOfBooks: Book[] = [
  {
    title:
      'Dragon Of The Titans',
    genre:
      'fantasy',
    publicationYear: 1992,
  },
  {
    title:
      'Queen Of Spring',
    genre:
      'drama',
    publicationYear: 2005,
  },
  {
    title:
      'Wolves Of The King',
    genre:
      'fantasy',
    publicationYear: 1988,
  },
];

// Use a common function to retrieve books
const filterArrayByValue = (
  items: Book[],
  propertyName: string,
  valueToFilter: string
): Book[] => {
  return items.filter(
    item =>
      item[
        propertyName
      ] ===
      valueToFilter
  );
};

// Call the function
// The result is an array with two books: "Dragon Of The Titans" and  "Wolves Of The King"
console.log(
  filterArrayByValue(
    listOfBooks,
    'genre',
    'fantasy'
  )
);