write array to csv nodejs code example

Example 1: 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 2: create csv file nodejs

const createCsvWriter = require('csv-writer').createObjectCsvWriter;
const csvWriter = createCsvWriter({
  path: 'out.csv',
  header: [
    {id: 'name', title: 'Name'},
    {id: 'surname', title: 'Surname'},
    {id: 'age', title: 'Age'},
    {id: 'gender', title: 'Gender'},
  ]
});

const data = [
  {
    name: 'John',
    surname: 'Snow',
    age: 26,
    gender: 'M'
  }, {
    name: 'Clair',
    surname: 'White',
    age: 33,
    gender: 'F',
  }, {
    name: 'Fancy',
    surname: 'Brown',
    age: 78,
    gender: 'F'
  }
];

csvWriter
  .writeRecords(data)
  .then(()=> console.log('The CSV file was written successfully'));

Example 3: js array to csv

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

Example 4: convert array to csv javascript

var objectToCSVRow = function(dataObject) {
    var dataArray = new Array;
    for (var o in dataObject) {
        var innerValue = dataObject[o]===null?'':dataObject[o].toString();
        var result = innerValue.replace(/"/g, '""');
        result = '"' + result + '"';
        dataArray.push(result);
    }
    return dataArray.join(' ') + '\r\n';
}

var exportToCSV = function(arrayOfObjects) {

    if (!arrayOfObjects.length) {
        return;
    }

    var csvContent = "data:text/csv;charset=utf-8,";

    // headers
    csvContent += objectToCSVRow(Object.keys(arrayOfObjects[0]));

    arrayOfObjects.forEach(function(item){
        csvContent += objectToCSVRow(item);
    }); 

    var encodedUri = encodeURI(csvContent);
    var link = document.createElement("a");
    link.setAttribute("href", encodedUri);
    link.setAttribute("download", "customers.csv");
    document.body.appendChild(link); // Required for FF
    link.click();
    document.body.removeChild(link); 
}