Parse CSV Text into Objects in JavaScript (Exercise)

The challenge

Write parseCsv(text). The first line holds the column names; each following line is a record. Return an array of objects. Ignore empty lines. All values stay as strings.

Example

parseCsv("name,town\nMia,Paris\nOmar,Oslo")
// [{ name: "Mia", town: "Paris" }, { name: "Omar", town: "Oslo" }]

Try it

Write your answer below, then press Check my answer. Your code runs right here in your browser, and the tests tell you what works.

Your solution

It prints

What the tests check

parseCsv("name,town\nMia,Paris\nOmar,Oslo") gives [{ name: "Mia", town: "Paris" }, { name: "Omar", town: "Oslo" }]
Empty lines are ignored: parseCsv("a,b\n1,2\n\n") gives [{ a: "1", b: "2" }]
parseCsv("x") gives []

Hints

Stuck? Open one hint at a time. Try again after each one.

Hint 1

text.split("\n") gives the lines. filter out the empty ones.

Hint 2

Destructure the header: const [header, ...rows] = lines;

Hint 3

Object.fromEntries(keys.map((k, i) => [k, values[i]])) builds an object from two arrays.

A solution

There’s always more than one right way. Read it, make sure you understand it, then try writing it yourself without looking.

Show one possible solution

Solution

function parseCsv(text) {
  const lines = text.split("\n").filter((line) => line.trim() !== "");
  const [header, ...rows] = lines;
  const keys = header.split(",");
  return rows.map((row) => {
    const values = row.split(",");
    return Object.fromEntries(keys.map((k, i) => [k, values[i]]));
  });
}

Learn what you need

This exercise uses what Junior Year: Modules, Node.js & npm: Working Like a Pro teaches. Read those notes first if any of it is new.

Parse CSV text into objects