30-seconds-of-code/snippets/arrayToCSV.md

title, tags, expertise, cover, firstSeen, lastUpdated

title	tags	expertise	cover	firstSeen	lastUpdated
Array to CSV	array,string	intermediate	blog_images/sunrise-over-city.jpg	2018-06-27T20:26:43+03:00	2020-11-03T21:55:08+02:00

Converts a 2D array to a comma-separated values (CSV) string.

• Use Array.prototype.map() and Array.prototype.join() to combine individual 1D arrays (rows) into strings, using the provided delimiter.
• Use Array.prototype.join() to combine all rows into a CSV string, separating each row with a newline (\n).
• Omit the second argument, delimiter, to use a default delimiter of ,.

const arrayToCSV = (arr, delimiter = ',') =>
  arr
    .map(v =>
      v.map(x => (isNaN(x) ? `"${x.replace(/"/g, '""')}"` : x)).join(delimiter)
    )
    .join('\n');

arrayToCSV([['a', 'b'], ['c', 'd']]); // '"a","b"\n"c","d"'
arrayToCSV([['a', 'b'], ['c', 'd']], ';'); // '"a";"b"\n"c";"d"'
arrayToCSV([['a', '"b" great'], ['c', 3.1415]]);
// '"a","""b"" great"\n"c",3.1415'