Modify Code - Convert File To CSV. Google Apps Script / Google sheets - google-apps-script

Question

The below code does as intended - except it ONLY copies the first 3 columns - and I need it to copy all the Data on the spreadsheet.I thought when the code says sheet.getDataRange(); that means all data but not in this case. Could I get a brief explanation of the issue rather than just the answer - love to know why 3 columns only are being selected.
function STCSV() {
var ss = SpreadsheetApp.openById("");
var sheets = ss.getSheets();
var sheet = sheets[3];
var formattedDate = Utilities.formatDate(new Date(), "GMT+10", "dd-MM-yyyy' '");
// append ".csv" extension to the sheet name
fileName = formattedDate + SpreadsheetApp.getActiveSpreadsheet().getName() + " ST CSV IMPORT " +
".csv";
var folder = DriveApp.getFolderById("");
// convert all available sheet data to csv format
var csvFile = convertRangeToCsvFile_(fileName, sheet);
// create a file in the Docs List with the given name and the csv data
var file = folder.createFile(fileName, csvFile);
}
function convertRangeToCsvFile_(csvFileName, sheet) {
// get available data range in the spreadsheet
var activeRange = sheet.getDataRange();
var data = activeRange.getValues();
var csvFile = undefined;
// loop through the data in the range and build a string with the csv data
if (data.length > 1) {
var csv = "";
for (var row = 0; row < data.length; row++) {
for (var col = 0; col < data[row].length; col++) {
if (data[row][col].toString().indexOf(",") != -1) {
data[row][col] = "\"" + data[row][col] + "\"";
}
}
// join each row's columns
// add a carriage return to end of each row, except for the last one
if (row < data.length-1) {
csv += data[row].join(",") + "\r\n";
}
else {
csv += data[row];
}
}
csvFile = csv;
}
return csvFile;
}
Appreciate any help. Thanks

Answer 1

The getDataRange() method returns a range corresponding to the dimensions in which data is present; therefore, the sheet.getDataRange() does return all the data from the sheet.
The reason only 3 columns are selected is because your sheet actually has only 3 columns.
Reference
Sheet Class Apps Script - getDataRange().