Accessing Parsed CSV data , CSV-Parser Node.js

I came here to find the solution to the same issue. Since this is an async operation, what works here is to call that function that acts on your parsed data once the end handler is called. Something like this should work in this situation:

const csv = require('csv-parser');
const fs = require('fs');
const results = [];

fs.createReadStream('demo.csv')
.pipe(csv())
.on('data', (data) => results.push(data))
.on('end', () => {
    console.log(results);
    csvData(results);
});

const csvData = ((csvInfo) => {
    console.log(csvInfo);
    console.log(csvInfo.length);
})

I can get results in .on('end', () => { console.log(results);}); , but if I put a console.log() after the createReadStream , results is undefined, does that make sense? – Videoaddict101

Your stream acts asynchronously, that means your data and your end handler will be called later, meanwhile your javascript continue to be executed. So accessing your array just after fs.createReadStream instruction will result of an empty array.

Understanding async is very important using javascript, even more for nodejs.

Please have a look on differents resources for handling async like Promise, Async/Await ...

You should you neat-csv which is the endorsed wrapper for csv-parser that gives you a promise interface.

That said, you can create a promise and resolve it in the on("end", callback)

import fs from "fs";
import csv from "csv-parser";

function getCsv(filename) {
  return new Promise((resolve, reject) => {
    const data = [];
    fs.createReadStream(filename)
      .pipe(csv())
      .on("error", (error) => reject(error))
      .on("data", (row) => data.push(row))
      .on("end", () => resolve(data));
  });
}

console.log(await getCsv("../assets/logfile0.csv"));