JavaScript .CSV to Arrays

Question

I have a .CSV file. It has 4 columns and thousands of rows. I want to have 4 arrays, one for each column. I recently started learning JavaScript. Can someone please tell me how to do this? In Python, this is extremely easy -- just a couple lines of code. However, I got super confused after seeing related posts in JS. Any help is greatly appreciated!

(PS: Please let me know if I need to "import" anything. Any references will be very helpful too!)

Answer 1

CSV can be tricky because cells can have escaped commas - comma-separated-values looks like a good choice since it is RFC 4180 compliant:

To install the package:

npm install comma-separated-values --save

And then to use it your app:

import CSV from 'comma-separated-values';

const csv = new CSV(data, {header: true}).parse();

That will result in an array of arrays (of rows) - to transform that into an array of arrays (of columns):

const cols = [[],[],[],[]];
csv.forEach(row => {
  row.forEach((cell, idx) => {
    cols[idx].push(cell);
  });
})