How can I parse a CSV string with JavaScript, which contains comma in data?

Question

I have the following type of string

var string = "\'string, duppi, du\', 23, lala"

I want to split the string into an array on each

Answer 1

RFC 4180 solution

This does not solve the string in the question since its format is not conforming with RFC 4180; the acceptable encoding is escaping double quote with double quote. The solution below works correctly with CSV files d/l from google spreadsheets.

UPDATE (3/2017)

Parsing single line would be wrong. According to RFC 4180 fields may contain CRLF which will cause any line reader to break the CSV file. Here is an updated version that parses CSV string:

'use strict';

function csvToArray(text) {
    let p = '', row = [''], ret = [row], i = 0, r = 0, s = !0, l;
    for (l of text) {
        if ('"' === l) {
            if (s && l === p) row[i] += l;
            s = !s;
        } else if (',' === l && s) l = row[++i] = '';
        else if ('\n' === l && s) {
            if ('\r' === p) row[i] = row[i].slice(0, -1);
            row = ret[++r] = [l = '']; i = 0;
        } else row[i] += l;
        p = l;
    }
    return ret;
};

let test = '"one","two with escaped """" double quotes""","three, with, commas",four with no quotes,"five with CRLF\r\n"\r\n"2nd line one","two with escaped """" double quotes""","three, with, commas",four with no quotes,"five with CRLF\r\n"';
console.log(csvToArray(test));

OLD ANSWER

(Single line solution)

function CSVtoArray(text) {
    let ret = [''], i = 0, p = '', s = true;
    for (let l in text) {
        l = text[l];
        if ('"' === l) {
            s = !s;
            if ('"' === p) {
                ret[i] += '"';
                l = '-';
            } else if ('' === p)
                l = '-';
        } else if (s && ',' === l)
            l = ret[++i] = '';
        else
            ret[i] += l;
        p = l;
    }
    return ret;
}
let test = '"one","two with escaped """" double quotes""","three, with, commas",four with no quotes,five for fun';
console.log(CSVtoArray(test));

And for the fun, here is how you create CSV from the array:

function arrayToCSV(row) {
    for (let i in row) {
        row[i] = row[i].replace(/"/g, '""');
    }
    return '"' + row.join('","') + '"';
}

let row = [
  "one",
  "two with escaped \" double quote",
  "three, with, commas",
  "four with no quotes (now has)",
  "five for fun"
];
let text = arrayToCSV(row);
console.log(text);