Definition of XML in JavaScript code example

Example: Working with XML in JavaScript

/*
    This code comes from Vincent Lab
    And it has a video version linked here: https://www.youtube.com/watch?v=5YQXVgNZvRk
*/

// Import dependencies
const fs = require("fs");
const { parseString, Builder } = require("xml2js");

// Load the XML
const xml = fs.readFileSync("data.xml").toString();
parseString(xml, function (err, data) {

    // Show the XML
    console.log(data);

    // Modify the XML
    data.people.person[0].$.id = 2;

    // Saved the XML
    const builder = new Builder();
    const xml = builder.buildObject(data);
    fs.writeFileSync("data.xml", xml, function (err, file) {
        if (err) throw err;
        console.log("Saved!");
    });

});