json2csv_example.js

const {
  Parser,
  transforms: { flatten, unwind }
} = require("json2csv");

try {
  const parser = new Parser({
    fields: ["firstColumn", "b.secondColumn", "cars.0.brand", "cars.1.brand"],
    transforms: [flatten({ arrays: true }), unwind({ paths: ["cars"] })]
  });
  const csv = parser.parse({
    firstColumn: "first data",
    b: {
      secondColumn: "second data"
    },
    cars: [{ brand: "AUDI" }, { brand: "TOYOTA" }]
  });
  console.log(csv);
//   OUTPUT:
//  "firstColumn","b.secondColumn","cars.0.brand","cars.1.brand"
//  "first data","second data","AUDI","TOYOTA"
} catch (err) {
  console.log(err);
}