JS: Turn CSV string, to: Object (map)

Question

How to code a pure JS.

To transform CSV string:

col1,col2\na,b\nc,d

Into this object structure:

{"a":["a","b"],"c":["c","d"]...}

So it can br refered by eg.: Obj.c, to return:

["c","d"]

Try to turn: "col1,col2\na,b\nc,d";

into an array of array: [['a','b'],['c','d']];

Calling this: CSVToArray("col1,col2\na,b\nc,d",",", true);

const CSVToArray = (data, delimiter = ",", omitFirstRow = false) =>
data.slice(omitFirstRow ? data.indexOf("\n") + 1 : 0).split("\n").map(v => v.split(delimiter));

What about turn "col1,col2\na,b\nc,d"; into readable referral object structure (by first item on each line)?

var Obj = {
 "a":["a","b"],
 "c":["c","d"],
 ...
 }

Answer 1

Use Object.fromEntries() to turn an array of [key, value] into an object with key: value properties.

const CSVToObject = (data, delimiter = ",", omitFirstRow = false) =>
 Object.fromEntries(data.split("\n").slice(omitFirstRow ? 1 : 0).map(v => {
 let fields = v.split(delimiter);
 return [fields[0], fields];
 }));
console.log(CSVToObject("col1,col2\na,b\nc,d", ",", true));