chore: add JS only higher order functions lab to frontend cert

frontend-cert/js-projects/higher-order-functions/script.js

@@ -0,0 +1,48 @@
+function sortByYear(book1, book2) {
+  if (book1.release_year < book2.release_year) {
+    return -1;
+  }
+
+  if (book1.release_year < book2.release_year) {
+    return 1;
+  }
+
+  return 0;
+}
+
+const books = [
+  {
+    title: "The Great Gatsby",
+    author_name: "F. Scott Fitzgerald",
+    release_year: 1925,
+  },
+  {
+    title: "In Search of Lost Time",
+    author_name: "Marcel Proust",
+    release_year: 1913,
+  },
+  {
+    title: "Ulysses",
+    author_name: "James Joyce",
+    release_year: 1922,
+  },
+  {
+    title: "One Hundred Years of Solitude",
+    author_name: "Gabriel García Márquez",
+    release_year: 1967,
+  },
+  {
+    title: "The Catcher in the Rye",
+    author_name: "J. D. Salinger",
+    release_year: 1951,
+  },
+];
+
+let filteredBooks = books.filter((book) => book.release_year < 1950);
+
+let filteredBooksSorted = filteredBooks.sort(sortByYear);
+
+console.log("Books Written Before 1950 (sorted according to release year)");
+filteredBooksSorted.forEach((book) => {
+  console.log(`${book.title} by ${book.author_name} (${book.release_year})`);
+});

frontend-cert/js-projects/higher-order-functions/user-stories.md

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+You should have an array of objects named `books` where each object in the array should have a string `title`, another string `author_name`, and a number `release_year`.
+
+You should call the filter higher-order function on the `books` array with a callback to filter out books written after a certain year such as 1950 and save the filtered array in a new array named `filteredBooks`.
+
+You should call the `sort` higher order function on the `filteredBooks` array to filter the books according to their `release_year` in ascending order and save the filtered array in a new array named `filteredBooksSorted`.
+
+You should have a callback function named `sortByYear` that accepts two books, `book1`, and `book2` as parameter for sorting the array.
+
+The `sortByYear` function should return `-1` if the `release_year` of `book1` object is smaller than that of the `book2` object.
+
+The `sortByYear` function should return `1` if the `release_year` of `book1` object is bigger than that of the `book2` object.
+
+The `sortByYear` function should return `0` for all other scenarios.
+
+You should call the `forEach` higher order function on the `filteredBooksSorted` array and print out the details of each book following the `<BOOK_TITLE> by <BOOK_AUTHOR> (<RELEASE_YEAR>)` format.