Build a Heritage Library Catalog - Step 28

JavaScript
1

Tell us what’s happening:

I do not understand the exercise.

It says “Build a row string with four fields”, I don’t understand what to do. Maybe it’s because english is my second language, but I literally do not understand, what this exercise wants from me. I can’t visualize it or anything.

Does it want me to make a 2-Dimensional-Array or something else?
Please help, thanks

Your code so far

const rawCatalogCards = [
  "From a Buick 8 | King, Stephen | 2002 | Shelf K7",
  "The Shining | King, Stephen | 1977 | Shelf K1",
  "The Stand | King, Stephen | 1978 | Shelf K2",
  "It | King, Stephen | 1986 | Shelf K3",
  "Misery | King, Stephen | 1987 | Shelf K4",
  "Do Androids Dream of Electric Sheep? | Dick, Philip K. | 1968 | Shelf D5",
  "I, Robot | Asimov, Isaac | 1950 | Shelf A8",
  "Foundation | Asimov, Isaac | 1951 | Shelf A9",
  "Dune | Herbert, Frank | 1965 | Shelf H3",
  "Neuromancer | Gibson, William | 1984 | Shelf G8",
  "Snow Crash | Stephenson, Neal | 1992 | Shelf S6",
  "The Martian | Weir, Andy | 2011 | Shelf W5",
  "Ender's Game | Card, Orson Scott | 1985 | Shelf C2",
  "The Hitchhiker's Guide to the Galaxy | Adams, Douglas | 1979 | Shelf A1",
  "Ready Player One | Cline, Ernest | 2011 | Shelf C7",
  "The Dark Tower: The Gunslinger | King, Stephen | 1982 | Shelf K5",
  // edge cases: missing data
  "Unknown Title |  | 1975 | Shelf X1",
  "Mysterious Manuscript | Unknown Author |  | Shelf Z9",
  "Ancient Scroll | Anonymous | 850 | ",
];

function parseCard(rawString) {
  const parts = rawString.split("|");
  const trimmedParts = [];
  for (let i = 0; i < parts.length; i++) {
    trimmedParts.push(parts[i].trim());
  }
  const title = trimmedParts[0];
  const author = trimmedParts[1];
  const year = trimmedParts[2];
  const location = trimmedParts[3];
  return {
    title: title || "Unknown",
    author: author || "Unknown",
    year: year ? parseInt(year) : "Unknown",
    location: location || "Unknown"
  };
}

function parseCatalog(rawCards) {
  const catalog = [];
  for (let i = 0; i < rawCards.length; i++) {
    catalog.push(parseCard(rawCards[i]));
  }
  return catalog;
}

const catalog = parseCatalog(rawCatalogCards);

function findByAuthor(catalog, author) {
  const searchTerm = author.toLowerCase();
  const results = [];
  for (let i = 0; i < catalog.length; i++) {
    if (catalog[i].author.toLowerCase().includes(searchTerm)) {
      results.push(catalog[i]);
    }
  }
  return results;
}

function groupByDecade(catalog) {
  const grouped = {};
  for (let i = 0; i < catalog.length; i++) {
    const book = catalog[i];
    if (book.year === "Unknown") {
      if (!grouped["Unknown"]) {
        grouped["Unknown"] = [];
      }
      grouped["Unknown"].push(book);
      continue;
    }
    const decade = Math.floor(book.year / 10) * 10;
    const decadeKey = `${decade}s`;
    if (!grouped[decadeKey]) {
      grouped[decadeKey] = [];
    }
    grouped[decadeKey].push(book);
  }
  return grouped;
}

const byDecade = groupByDecade(catalog);

function renderEntry(entry) {
  const title = entry.title || "Unknown";
  const author = entry.author || "Unknown";
  const year = entry.year || "Unknown";
  const location = entry.location || "Unknown";
  return `${"-".repeat(25)}
Title: ${title}
Author: ${author}
Year: ${year}
Location: ${location}
${"-".repeat(25)}`;
}

console.log(renderEntry(catalog[0]));

function validateEntry(entry) {
  let isValid = true;
  if (!("title" in entry) || !entry.title || entry.title === "Unknown") {
    isValid = false;
  }
  if (!("author" in entry) || !entry.author || entry.author === "Unknown") {
    isValid = false;
  }
  if (!("year" in entry) || !entry.year || entry.year === "Unknown") {
    isValid = false;
  }
  if (!("location" in entry) || !entry.location || entry.location === "Unknown") {
    isValid = false;
  }
  return isValid;
}

function exportToJSON(catalog) {
  return JSON.stringify(catalog, null, 2);
}

function exportToCSV(catalog) {
  const header = "Title,Author,Year,Location";
  const rows = [];

// User Editable Region

  for (let i = 0; i < catalog.length; i++){
    const entry = catalog[i];
  }

// User Editable Region

}

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:150.0) Gecko/20100101 Firefox/150.0

Challenge Information:

Build a Heritage Library Catalog - Step 28

2

No 2-dimensional array needed.

CSV is basically just plain text, and each “row” is a line of text. The values in that line are separated by commas.

So for a book entry like this:

{title: “From a Buick 8”, author: “King, Stephen”, year: 2002, location: “Shelf K7”}

the CSV row should look like this:

“From a Buick 8”,“King, Stephen”,2002,“Shelf K7”

The string fields need double quotes because they can contain commas, for example “King, Stephen”. Without the quotes, the comma inside the author name would be mistaken as a separator.

3

I came here because I also didn’t understand ““Build a row string with four fields”. Think about template literals as tools for building strings.

4

So I tried to recreate what you recommended, but I’m doing something wrong

Here’s the code for the exportToCSV function:

function exportToCSV(catalog) {

  const header = "Title,Author,Year,Location";

  const rows = [];

  for (let i = 0; i < catalog.length; i++){

    const entry = catalog[i];

    rows.push(`"${entry["title"]}","${entry["author"]}",${entry["year"]},"${entry["location"]}"`);

  }

}

The output would be: ‘“From a Buick 8”,“King, Stephen”,2002,“Shelf K7”’

the single quotes are still visible on the outer edges and I still don’t know what to do with the header, if that has any use.

I genuinely don’t know what this exercise is trying to do

5

Got the solution, you’re FORCED to use dot notation