js create csv file code example

Example 1: Working with CSV in JavaScript

/*
    This code comes from Vincent Lab
    And it has a video version linked here: https://www.youtube.com/watch?v=95wAbrQAm5g
*/

// Import dependencies
const fs = require("fs");
const csv = require("csvtojson");
const { Parser } = require("json2csv");

(async () => {

    // Load the cars
    const cars = await csv().fromFile("cars.csv");

    // Show the cars
    console.log(cars);

    // Modify the cars
    cars[0].Year = 1998;

    // Saved the cars
    const carsInCsv = new Parser({ fields: ["Year", "Make", "Model", "Length"] }).parse(cars);
    fs.writeFileSync("cars.csv", carsInCsv);

})();

Example 2: create csv file nodejs

const csv = require('csv-parser');
const fs = require('fs');

fs.createReadStream('data.csv')
  .pipe(csv())
  .on('data', (row) => {
    console.log(row);
  })
  .on('end', () => {
    console.log('CSV file successfully processed');
  });

Example 3: create csv file javascript

$("#download_1").click(function() {
var json_pre = '[{"Id":1,"UserName":"Sam Smith"},{"Id":2,"UserName":"Fred Frankly"},{"Id":1,"UserName":"Zachary Zupers"}]';
var json = $.parseJSON(json_pre);

var csv = JSON2CSV(json);
var downloadLink = document.createElement("a");
var blob = new Blob(["\ufeff", csv]);
var url = URL.createObjectURL(blob);
downloadLink.href = url;
downloadLink.download = "data.csv";

document.body.appendChild(downloadLink);
downloadLink.click();
document.body.removeChild(downloadLink);
});

Example 4: create csv file javascript

function JSON2CSV(objArray) {
    var array = typeof objArray != 'object' ? JSON.parse(objArray) : objArray;
    var str = '';
    var line = '';

    if ($("#labels").is(':checked')) {
        var head = array[0];
        if ($("#quote").is(':checked')) {
            for (var index in array[0]) {
                var value = index + "";
                line += '"' + value.replace(/"/g, '""') + '",';
            }
        } else {
            for (var index in array[0]) {
                line += index + ',';
            }
        }

        line = line.slice(0, -1);
        str += line + '\r\n';
    }

    for (var i = 0; i < array.length; i++) {
        var line = '';

        if ($("#quote").is(':checked')) {
            for (var index in array[i]) {
                var value = array[i][index] + "";
                line += '"' + value.replace(/"/g, '""') + '",';
            }
        } else {
            for (var index in array[i]) {
                line += array[i][index] + ',';
            }
        }

        line = line.slice(0, -1);
        str += line + '\r\n';
    }
    return str;
}

Example 5: combine csv files javascript

var file1 = appRoot + '\\csvFiles\\details1.csv';
var file2 = appRoot + '\\csvFiles\\idetails2.csv';
var stream = fs.createReadStream(file1);
var stream2 = fs.createReadStream(file2);
var fileData1 = [],
    fileData2 = [],
    i = 0;

csv.fromStream(stream).on("data", function(data) {
    fileData1.push(data);
}).on("end", function() {
    csv.fromStream(stream2).on("data", function(data) {
        if (i != 0) {
            fileData2.push(data);
        }
        i++;
    }).on("end", function() {
        console.log("done");
        var fileData3 = fileData1.concat(fileData2);
        csv.writeToPath("outputfile.csv", fileData3).on("finish", function() {
            res.send('Done merge');
        });
    });
});