Converts a 2D array to a comma-separated values (CSV) string. Use Array.prototype.map() and Array.prototype.join(delimiter) to combine individual 1D arrays (rows) into strings. Use Array.prototype.join('\n') to combine all rows into a CSV string, separating each row with a newline. Omit the second argument, delimiter, to use a default delimiter …

arrayToCSV.js

const arrayToCSV = (arr, delimiter = ',') =>
  arr.map(v => v.map(x => `"${x}"`).join(delimiter)).join('\n');